THRIFT-2835 Add possibility to distribute generators separately from thrift core, and load them dynamically
Client: Compiler
Patch: Nobuaki Sukegawa, rebased by dtmuller

Also fixed by dtmuller:
* Add plugin namespace for erlang language binding
* Fix unit test test_const_value
* Don't clear type cache with every t_program conversion
* Type "wb" may not be supported by popen on non-Windows platforms
* Fix constness of AST type signatures
diff --git a/lib/cpp/test/Makefile.am b/lib/cpp/test/Makefile.am
index 4e76ce8..6f46117 100755
--- a/lib/cpp/test/Makefile.am
+++ b/lib/cpp/test/Makefile.am
@@ -358,7 +358,7 @@
 gen-cpp/ChildService.cpp gen-cpp/ChildService.h gen-cpp/ParentService.cpp gen-cpp/ParentService.h gen-cpp/proc_types.cpp gen-cpp/proc_types.h: processor/proc.thrift
 	$(THRIFT) --gen cpp:templates,cob_style $<
 
-AM_CPPFLAGS = $(BOOST_CPPFLAGS) -I$(top_srcdir)/lib/cpp/src -D__STDC_LIMIT_MACROS
+AM_CPPFLAGS = $(BOOST_CPPFLAGS) -I$(top_srcdir)/lib/cpp/src -D__STDC_LIMIT_MACROS -I.
 AM_LDFLAGS = $(BOOST_LDFLAGS)
 AM_CXXFLAGS = -Wall -Wextra -pedantic