Support for complex (multikey) lua scripts and minor refactor of lua handling.

Ranking methods for ranking lists according to length and sets according to size.
Merge branch 'master' into feature/rankers

Conflicts:
	hot_redis/tests.py
	hot_redis/types.py
Merge branch 'master' into feature/rankers

Conflicts:
	hot_redis/tests.py
	hot_redis/types.py
Merge pull request #4 from jmizgajski/feature/rankers

Support for complex (multikey) lua scripts and minor refactor of lua han...