Added block comment and inline comment to PegFile grammar
Added property for base grammar
Fix bug in generated code for optional expressions
Added features for actual behavior of the parsers that are generated
Bugfix: last element of a sequence was not returned
Regenerated parser after bugfix
Parse extended grammars
Make start symbol optional
Make 'start' a reserved keyword
Move startSymbol from constructor to setter
Generate extended grammars and other grammars without start symbols