Cleanups of deps and ignores for conformance

- Hopefully complete the deps for other languages for the generated conformance proto sources.
- List the generated sources for cleanup by make's clean rules.
- Make the toplevel nuke the pyc files that can get created in the ObjC dir.
diff --git a/.gitignore b/.gitignore
index a9b0a88..b0a92f8 100644
--- a/.gitignore
+++ b/.gitignore
@@ -101,8 +101,11 @@
 conformance/.libs/
 conformance/com/
 conformance/conformance-cpp
+conformance/conformance-csharp
+conformance/conformance-java
 conformance/conformance-test-runner
 conformance/conformance.pb.cc
 conformance/conformance.pb.h
 conformance/conformance.rb
+conformance/javac_middleman
 conformance/protoc_middleman