Align params with sassC

[cbosdo]

The C implementation of sassc has slightly different parameters. It would be nice to harmonize those for them to be exchangeable. See here for the sassC parameters. Note that I don't know which of libsass-python or sassC came first, and which set of params should be used as a reference.

[asottile]

Quite a few of sassc's options are specific to their implementation so I don't think we'd pick up all of them. The others should match reasonably well but I imagine there's some we should change to be more like them.

[cbosdo]

Maybe not all should be aligned indeed. The one I had in mind is -s <style> vs -t <style>.

[mgreter]

Ruby sass uses -t for output style, which is why sassc (and perl-libsass cli) also go with -t :)

[asottile]

#130 added --source-comments