THRIFT-3382 - C++: TBase class for generated structs added

Client: C++
Patch: Adam Beberg <beberg@sentient.ai>

TBase.h is now part of C++ Thrift library and TBase
is used as base class for all structs generated from
user defined structs (when not generating in template mode)

This closes #653
diff --git a/lib/cpp/Makefile.am b/lib/cpp/Makefile.am
index 80e8917..dac840a 100755
--- a/lib/cpp/Makefile.am
+++ b/lib/cpp/Makefile.am
@@ -159,7 +159,8 @@
                          src/thrift/TApplicationException.h \
                          src/thrift/TLogging.h \
                          src/thrift/cxxfunctional.h \
-                         src/thrift/TToString.h
+                         src/thrift/TToString.h \
+                         src/thrift/TBase.h
 
 include_concurrencydir = $(include_thriftdir)/concurrency
 include_concurrency_HEADERS = \