Rough draft of brace tool

Tool to add braces to files. Braces in comments help Vim fold python
better than whitespace.
Reorganized Functions

Added two new functions to handle the two passes. The find_keywords
does the first pass line number finding. The add_braces adds the
opening/closing lines where needed. The main function writes the
file back to disk.
Added argument parser

Script now parses 'limit' and 'prefix' flags. Limit tells how
big the gap must be before braces will be added. Prefix changes
the output destination file by adding a prefix.
Fixed find_closure()

Comments should not be included when trying to find indentation
changes since they are not bound by the same whitespace rules.
Function now disregards comments in additon to blank lines.