use compressed RPNs internally, and fix issue GC#1 E-PR-0010
improved compatibility to java 6+ instead of java 7
added no convert work vars option to unify menu
refactoring + reformat doesn't require save
bugfix
bugfix
bugfix
better error reporting on compressed proofs
optional varhyps (dummy vars) can be anywhere in the parens of a compressed proof
new compression algorithm, and new parsetree squish algorithm