Trebuchet : Icon edit dialog fixes

Append text rather than setText for the edit dialog title, so that the
cursor moves to the end.

Keep track of customIconResource state to ensure its not reset.

Preserve custom icons when the linking application is updated

Change-Id: Icab0f0ce45f1dbb79ce895228303aa2c944f1213
Merge remote-tracking branch 'cm/cm-10.2' into cm-10.2