Reformat RePair
Reformat code
Remove unused import
Make PairBuffer arrays final and non-private to allow unit tests to access
Use standard CharSequence for input rather than our own TextIterator interface
Comment fixes
Remove unnecessary arry fill with zeroes since the array defaults to
zeroes
Add @Override declarations
Hardcode separator symbol as \uFFFF instead of having it user definable
Refactor to support Unicode (untested)