Last piece of Windows support.

YCM should now compile cleanly on MSVC. Fixes #19.

cpp/ycm/ycm_core.cpp

@@ -155,3 +155,10 @@ BOOST_PYTHON_MODULE(ycm_core)
 
 #endif // USE_CLANG_COMPLETER
 }
+
+// Boost.Thread forces us to implement this.
+// We don't use any thread-specific (local) storage so it's fine to implement
+// this as an empty function.
+namespace boost {
+void tss_cleanup_implemented() {}
+};