Fix ShadowDateFormat days and add unit tests to verify.

The formats now use a lower-case `d` (day-of-month) rather than a capital `D` (day-of-year).
Remove some more Colorish Shadows.
Remove a bunch of trivial Shadows in favor of AOSP.

None of these had interesting implementations and can be
satisfied by AOSP easily.
Remove PeriodicSyncShadow.
Merge pull request #869 from metalhead8816/remove_criteria

Remove a bunch of trivial Shadows in favor of AOSP.
Merge pull request #870 from metalhead8816/remove_periodic_sync

Remove PeriodicSyncShadow.
Merge pull request #868 from metalhead8816/color_matrix

Remove some more Colorish Shadows.
Merge pull request #864 from paulblessing/fix-date-formats

Fix ShadowDateFormat days