ParserGenApp should use ARC

`Feature Request` - Change to ARC

Is there a reason `ParserGenApp` is not using ARC?

Adding new code and functionality will be easier if we don't need to do `autorelease` etc. It will also be less error prone.

I can potentially see a reason not do do it in PegKit Framework if you are trying to maintain support for old code. But Cocoa pods can do that for you.