lark.lark didn't parse grammars that didn't have a trailing newline in the file, but lark itself has no problem parsing those grammars
this change makes lark.lark more accurate in reflecting what grammars are parsed by lark.
- @erezsh added the new Lark reference and some other things using the
current .g extension, so I wanted to resolve them for PR #117
- Renamed lark.g to lark.lark.
- Changed lark_grammar.py to use .lark file extensions.
- Changed urls that used .g to use .lark.