Make the C++ generator use non-hardcoded namespaces.

- Make the C++ generator use program->get_namespace("cpp")
  instead of program->get_cpp_namespace()
- Eliminate the explicit "cpp_namespace" in t_program.
- Deprecate the cpp_namespace token.
- Update example .thrift files and syntax files.


git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@665513 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/test/DocTest.thrift b/test/DocTest.thrift
index 5749fda..d760d9e 100755
--- a/test/DocTest.thrift
+++ b/test/DocTest.thrift
@@ -5,7 +5,7 @@
  */
 
 java_package thrift.test
-cpp_namespace thrift.test
+namespace cpp thrift.test
 
 // C++ comment
 /* c style comment */