Todo List

Primary:
 - (In Progress) Implement attribute validation
 - Implement HTMLPurifier (trivial)

Code issues:
 - Rename AbstractTest to Harness
 - (?) Create a TokenFactory to prevent really long lines
 - Massive profiling

Enhancements:
 - Do fixes for Firefox's inability to handle COL alignment props (Bug 915)
 - Have lexers strip out HTML and BODY tags rather than choke