Thrift: Update some makefiles to make "make dist" work.

Reviewed By: mcslee

Test Plan: Ran "make dist" and did a diff.

Revert Plan: ok


git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@665466 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/lib/csharp/Makefile.am b/lib/csharp/Makefile.am
index 3b88dbb..909bc53 100644
--- a/lib/csharp/Makefile.am
+++ b/lib/csharp/Makefile.am
@@ -35,3 +35,9 @@
 
 clean-local:
 	$(RM) Thrift.dll
+
+EXTRA_DIST = \
+             $(THRIFTCODE) \
+             ThriftMSBuildTask \
+             src/Thrift.csproj \
+             src/Thrift.sln