THRIFT-3762 Fix warnings for deprecated Thrift "byte" fields

This closes #967
diff --git a/test/DebugProtoTest.thrift b/test/DebugProtoTest.thrift
index df0fb30..b6a7659 100644
--- a/test/DebugProtoTest.thrift
+++ b/test/DebugProtoTest.thrift
@@ -36,7 +36,7 @@
 struct OneOfEach {
   1: bool im_true,
   2: bool im_false,
-  3: byte a_bite = 0x7f,
+  3: i8 a_bite = 0x7f,
   4: i16 integer16 = 0x7fff,
   5: i32 integer32,
   6: i64 integer64 = 10000000000,
@@ -45,7 +45,7 @@
   9: string zomg_unicode,
   10: bool what_who,
   11: binary base64,
-  12: list<byte> byte_list = [1, 2, 3],
+  12: list<i8> byte_list = [1, 2, 3],
   13: list<i16> i16_list = [1,2,3],
   14: list<i64> i64_list = [1,2,3]
 }
@@ -105,7 +105,7 @@
 
 struct CompactProtoTestStruct {
   // primitive fields
-  1: byte   a_byte;
+  1: i8     a_byte;
   2: i16    a_i16;
   3: i32    a_i32;
   4: i64    a_i64;
@@ -117,7 +117,7 @@
   10: Empty empty_struct_field;
 
   // primitives in lists
-  11: list<byte>    byte_list;
+  11: list<i8>      byte_list;
   12: list<i16>     i16_list;
   13: list<i32>     i32_list;
   14: list<i64>     i64_list;
@@ -128,7 +128,7 @@
   19: list<Empty>   struct_list;
 
   // primitives in sets
-  20: set<byte>     byte_set;
+  20: set<i8>       byte_set;
   21: set<i16>      i16_set;
   22: set<i32>      i32_set;
   23: set<i64>      i64_set;
@@ -140,30 +140,30 @@
 
   // maps
   // primitives as keys
-  29: map<byte, byte>             byte_byte_map;
-  30: map<i16, byte>              i16_byte_map;
-  31: map<i32, byte>              i32_byte_map;
-  32: map<i64, byte>              i64_byte_map;
-  33: map<double, byte>           double_byte_map;
-  34: map<string, byte>           string_byte_map;
-  35: map<binary, byte>           binary_byte_map;
-  36: map<bool, byte>             boolean_byte_map;
+  29: map<i8, i8>               byte_byte_map;
+  30: map<i16, i8>              i16_byte_map;
+  31: map<i32, i8>              i32_byte_map;
+  32: map<i64, i8>              i64_byte_map;
+  33: map<double, i8>           double_byte_map;
+  34: map<string, i8>           string_byte_map;
+  35: map<binary, i8>           binary_byte_map;
+  36: map<bool, i8>             boolean_byte_map;
   // primitives as values
-  37: map<byte, i16>              byte_i16_map;
-  38: map<byte, i32>              byte_i32_map;
-  39: map<byte, i64>              byte_i64_map;
-  40: map<byte, double>           byte_double_map;
-  41: map<byte, string>           byte_string_map;
-  42: map<byte, binary>           byte_binary_map;
-  43: map<byte, bool>             byte_boolean_map;
+  37: map<i8, i16>              byte_i16_map;
+  38: map<i8, i32>              byte_i32_map;
+  39: map<i8, i64>              byte_i64_map;
+  40: map<i8, double>           byte_double_map;
+  41: map<i8, string>           byte_string_map;
+  42: map<i8, binary>           byte_binary_map;
+  43: map<i8, bool>             byte_boolean_map;
   // collections as keys
-  44: map<list<byte> (python.immutable = ""), byte>       list_byte_map;
-  45: map<set<byte> (python.immutable = ""), byte>        set_byte_map;
-  46: map<map<byte,byte> (python.immutable = ""), byte>   map_byte_map;
+  44: map<list<i8> (python.immutable = ""), i8>       list_byte_map;
+  45: map<set<i8> (python.immutable = ""), i8>        set_byte_map;
+  46: map<map<i8,i8> (python.immutable = ""), i8>     map_byte_map;
   // collections as values
-  47: map<byte, map<byte,byte>>   byte_map_map;
-  48: map<byte, set<byte>>        byte_set_map;
-  49: map<byte, list<byte>>       byte_list_map;
+  47: map<i8, map<i8,i8>>     byte_map_map;
+  48: map<i8, set<i8>>        byte_set_map;
+  49: map<i8, list<i8>>       byte_list_map;
 }
 
 // To be used to test the serialization of an empty map
diff --git a/test/DocTest.thrift b/test/DocTest.thrift
index 70575c1..d702b2c 100644
--- a/test/DocTest.thrift
+++ b/test/DocTest.thrift
@@ -58,7 +58,7 @@
   1:  string string_thing
 
   /** doct text goes before a comma */
-  4:  byte   byte_thing,
+  4:  i8     byte_thing,
 
   9:  i32    i32_thing,
   11: i64    i64_thing
@@ -74,7 +74,7 @@
 
 struct Xtruct2
 {
-  1: byte   byte_thing,
+  1: i8     byte_thing,
   2: Xtruct struct_thing,
   3: i32    i32_thing
 }
@@ -117,7 +117,7 @@
   /** And this is how you would document functions in a service */
   void         testVoid(),
   string       testString(1: string thing),
-  byte         testByte(1: byte thing),
+  i8           testByte(1: byte thing),
   i32          testI32(1: i32 thing),
 
   /** Like this one */
diff --git a/test/StressTest.thrift b/test/StressTest.thrift
index ccf22af..431811b 100644
--- a/test/StressTest.thrift
+++ b/test/StressTest.thrift
@@ -24,12 +24,12 @@
 service Service {
 
   void echoVoid(),
-  byte echoByte(1: byte arg),
+  i8 echoByte(1: i8 arg),
   i32 echoI32(1: i32 arg),
   i64 echoI64(1: i64 arg),
   string echoString(1: string arg),
-  list<byte>  echoList(1: list<byte> arg),
-  set<byte>  echoSet(1: set<byte> arg),
-  map<byte, byte>  echoMap(1: map<byte, byte> arg),
+  list<i8>  echoList(1: list<i8> arg),
+  set<i8>  echoSet(1: set<i8> arg),
+  map<i8, i8>  echoMap(1: map<i8, i8> arg),
 }
 
diff --git a/test/ThriftTest.thrift b/test/ThriftTest.thrift
index 20929d4..56adf39 100644
--- a/test/ThriftTest.thrift
+++ b/test/ThriftTest.thrift
@@ -80,7 +80,7 @@
 struct Xtruct
 {
   1:  string string_thing,
-  4:  byte   byte_thing,
+  4:  i8     byte_thing,
   9:  i32    i32_thing,
   11: i64    i64_thing
 }
@@ -158,7 +158,7 @@
    * @param byte thing - the i8/byte to print
    * @return i8 - returns the i8/byte 'thing'
    */
-  i8         testByte(1: byte thing),
+  i8           testByte(1: i8 thing),
 
   /**
    * Prints 'testI32("%d")' with thing as '%d'
@@ -271,7 +271,7 @@
 
   /**
    * Prints 'testMulti()'
-   * @param byte arg0 -
+   * @param i8 arg0 -
    * @param i32 arg1 -
    * @param i64 arg2 -
    * @param map<i16, string> arg3 -
@@ -280,7 +280,7 @@
    * @return Xtruct - returns an Xtruct with string_thing = "Hello2, byte_thing = arg0, i32_thing = arg1
    *    and i64_thing = arg2
    */
-  Xtruct testMulti(1: byte arg0, 2: i32 arg1, 3: i64 arg2, 4: map<i16, string> arg3, 5: Numberz arg4, 6: UserId arg5),
+  Xtruct testMulti(1: i8 arg0, 2: i32 arg1, 3: i64 arg2, 4: map<i16, string> arg3, 5: Numberz arg4, 6: UserId arg5),
 
   /**
    * Print 'testException(%s)' with arg as '%s'
@@ -331,7 +331,7 @@
        1: i32 begin_in_both,
 
        2: i32 newint,
-       3: byte newbyte,
+       3: i8 newbyte,
        4: i16 newshort,
        5: i64 newlong,
        6: double newdouble