LDPI resources converted from HDPI, patch 1.

Images have been converted w/ imagemagick (-resize 50%, no unsharp/sharpen
as they seemed better) and optimized w/ optipng (-o7).
This first patchset covers the images which only exist in drawable-hdpi
and don't exist in drawable-ldpi (in the official repository).

Change-Id: I0af46bd7a62240a344bf59b0efed97acdd7c0e2b
Merge "LDPI resources converted from HDPI, patch 1." into cm-10.1