[REDESIGN] Rearrangement of AST system.

All the code about ASTs moves to a subpackage named 'syntax_tree'. Its
contents are are generated when the setup.py build_py command is run.
[FIX] Ignore all but __init__.py in syntax_tree

Remove auto-generated files from accessible committed file-tree.
[PACKAGING] Clean up packaging system

Py2C is now zip-safe.

Add MANIFEST.in.
Move ast_gen.py to root of repository.
Remove setup_helpers package.
[DEV-TOOLS] Added dev_tools directory

Convert all batch-based development scripts to Python scripts. They
reside in dev_tools directory.
Merge branch 're-arrange'