Merge branch 'master' into beta-improvements
Node Accessor interface improvements
Node Accessor bug fixed
Expression parser improvement
Line offset tracking
Lexer simplified
ParserSpec interface improved
Fragment forceful skipping/using bug fixed
Repetition rule bug fixed
Referential rule bug fixed
Empty monitor implemented
Monitor configuration bug fixed
Repetition rule with separator bug fixed
Comment erasing bug fixed
Bug in recovery mechanism fixed
Merge branch 'beta-improvements'

 - Bug fix:
   - Fragment forceful skipping/using, i.e comments erasing case.
   - Repetition rule bug.
   - Referential rule for without tag.
   - Choice Rule bug in selection of the suitable recoverable candidate.
 - Minor improvements:
   - Node construction in call-chain way.
   - Optional token consumption feature in Expression parser.
   - Line offset token tracking.
   - Syntax parser in ParserSpec can be instantiated separately from the lexer.
   - Empty Monitor that tracks nothing. For simple debug purposes.