LatinIME: add back shortcuts support

Revert
"am 12d80ebe: Remove shortcut support from LatinIME."
change fe674a44

Making sure to include unit test changes this time.
Adjust for deleted files and delete references to them
This reverts fe674a44
CYNGNOS-3129
CYNGNOS-3267

Change-Id: I136e307f93445b353e0d798284fd0fbaee61c0d9
(cherry picked from commit ed2ba122)