Support passing a moduleName for a single file compiles.
Add basic support for goog.module (Closure) based imports.

- option to enable Closure modules
- golden file based tests
- based on moduleName for the current file
- fails for export *
Fixed a regular expression in Makefile
Don't emit sourceURL unless output differs from input.

Add test.
Fixes #1583

Review URL: https://api.github.com/repos/google/traceur-compiler/issues/1584

Closes #1584, closes #1583.
fix a typo in SuperTransformer
Add support for member variable initializers