[MISC] Added Disclaimer Borders, Python 3 shebang

Added border to disclaimer on top of files. Cleaned and added disclaimer
to setup.py.
Changed all shebangs to Python 3.
[TESTS] Minor edits to tests.

Renamed variable in test_translator.
Removed the remove_comments method of ast_gen.Parser. It is now a
function.
[WIP] Added changes to _ast_gen to pass tests.

Moved 2 methods of _ast_gen.Parser out as functions in _ast_gen.py
Added doc-strings to code_generator.py.
[WIP-C] Complete work on dual_ast.py

The dual_ast system is complete. All Python level nodes are implemented.
[CLEANUP] Cleaned setup.py, readme, gitignore

Cleaned and modified names in the README. Added link to Milestones.
Made setup.py more consistent. Use nosetests command from nose to run
tests. Coverage is recorded from the root. The generated reports are
being placed in _coverage_reports directory in root.