Define 'setq-local' if it is not defined.

'setq-local' is introduced in Emacs 24.3.
Merge pull request #3 from syohex/under-24.3

Define 'setq-local' if it is not defined.
Adding appropriate licensing stuff to hy-mode
Merge pull request #4 from cwebber/8ae90fac3419152f6904c67481e69b1b9152a9c6

Added licensing info
Use constant-face for :keywords

This uses constant-face for everything that looks like a keyword:
something that starts with a :, and is terminated by whitespace, or
something that needs to get highlighted another way (eg, parens).

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>