Better common lisp support

[dieggsy]

Looking at the common lisp rules, things like defmethod, defclass, and defvar aren't supported. I would think at minimum these three should be added, since they're used everywhere in CL.

I'd be happy to open a PR if that's preferrable, though it may take me a minute to get around to it.

[jacktasia]

Thanks for opening this. A PR for these is definitely welcome.

[dieggsy]

I've added an initial pass at this in my fork which seems to be mostly working, but it looks like it's searching case-sensitively by default. Is there any way to change the case sensitivity or search options per language?

[phikal]

It looks like you are going to have to change the command generator functions (the ones set by :generate in dumb-jump-generators-by-searcher to insert a case-insensitivity flag when the language is case-insenstive. I'd say adding a defconst with case-insensitive languages (CL should be enough for now) would be the best way to do this.