Parser Grammar Engine (PGE) progress

PGE implements Perl 6 rule and parsing syntax

• Operator-precedence ("bottom-up") parser added to PGE
• "Rules" are now "regexes", "tokens", and "rules" ("Oh my!")
• Better support for grammars
• Closures in regexes
• Unicode
• Improved test suite (particle++)
• Simple Perl 5 regexes (610 of 800 tests passing)
• PGC - parser grammar compiler
• Utility rules
• Adverb modifiers