fix for label that exists as grammar and lexer rule
Replace [] elements with ()?
Replace n times optional {} with ()*
Comma replacement
Minus replacement
Added VHDL examples from OC
Merge pull request #1 from sebx86/master

- some ()*, ()? fixes
- LABEL is also a rule, moved to LABLE_KW and commented some synpreds
- VHDL examples added from opencores (AES core, CPU core and UART)