Allow the Thrift compiler to be built without the C# generator.

- Use AX_THRIFT_GEN to make configure support --disable-gen-csharp
- Update the compiler Makefile.am to exclude the generator.


git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@665610 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/configure.ac b/configure.ac
index 6d41505..e03675c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -130,6 +130,8 @@
 AM_CONDITIONAL([THRIFT_GEN_cpp], [test "$ax_thrift_gen_cpp" = "yes"])
 AX_THRIFT_GEN(java, [Java], yes)
 AM_CONDITIONAL([THRIFT_GEN_java], [test "$ax_thrift_gen_java" = "yes"])
+AX_THRIFT_GEN(csharp, [C#], yes)
+AM_CONDITIONAL([THRIFT_GEN_csharp], [test "$ax_thrift_gen_csharp" = "yes"])
 AX_THRIFT_GEN(cocoa, [Cocoa], yes)
 AM_CONDITIONAL([THRIFT_GEN_cocoa], [test "$ax_thrift_gen_cocoa" = "yes"])
 AX_THRIFT_GEN(st, [Smalltalk], yes)