Added ls-defines command

ls-defines: List all defined constants.
ls-defines --user: List all user-defined constants (get_defined_constants(true)['user']).
ls-defines --category date: Equivalent to get_defined_constants(true)['date'].
cleanup for CS (work in progress)
Merge pull request #15 from Future500/feature/super-ls

Feature/super-ls added support for defined constants