packages: some cleanup.

Hi Andrea,

Was looking through the code and did a few small cleanups if you're interested.

I didn't change the 2-spaces (we tend to use 4-spaces in the main repo).

Also, I think the use of ``current-project set-global`` isn't a good one.  Better would be to just use ``set``, depending on the ``get`` value in a word later at run-time is a little sketchy if you load two projects the value gets changed.  Better would be to somehow save it somewhere, if you want I could look into that.  For example, the way we do ``current-vocab``, ``manifest``, and ``current-library`` is set/get.

Best,