Melee range

Rewrites the majority of melee talents to check the talent's range field instead of hardcoding the distance.
This involved:
- Actually giving a range to talents that didn't have one.
- Replacing the range check with a call to canProject(tg, x, y)
- Moving many hardcoded tg values into a target field, and using getTalentTarget instead.
- Adding an is_melee and is_special_melee (shields) flag to talents (unnecessary, but potentially useful).

Also made it easier to have talents replace the Attack talent, like double strike.

I've run a character up through level 15, but otherwise haven't done much testing.