First attempt at integrating keep comments into Purify Engine
Completed keep comments option. Fixed previous issue. Still need to
nicely format the code.
Cleaned up code. Insert and remove Z tags code was abstracted into
methods. Not sure how to fix line break problem.
Keep Comments works well. Had a hard time integrating your changes so
the indentations happen. Ruined everything. Then took everything out.
Merge remote-tracking branch 'origin/matt'

Conflicts:
	StyleCleaner/src/main/java/processing/PurifyEngine.java
fix warning about AttributeAppender