Two more easy patches are awaiting commit, for those hunting for top RESLOVED/FIXED position: bugs 33494 and 33496.
Also, with the upcoming migration go GIT, I have a suggestion for another access group: /Skins. I do not really consider the skins/ directory to be part of core or extensions, as skins only relate to the client side.
For that matter, perhaps /Client would be another option, whouch would include both skins/ and resources/; all client-side components of MediaWiki.