Improve textmate grammars for procedure declarations

[thetarnav]

Took some time trying to improve the textmate grammars for procedure declarations.

It's not perfect, I'm still not sure how to do these parts:

• differentiate between procedure types and normal procedure declaration (right now they are both functions)
• supporting assigning with type specified (my_proc: Type : proc() {})
• differentiating between named return types and unnamed return types

Some of the patterns here could probably be reused for variable/struct declarations as well

[DanielGavin]

Thanks. I have no experience with textmate grammars, so it's better than what I could do.