Deteremine the script type of source cell during paste replication.

Doing this ahead of time eliminates the need to update script types of
all replicated cells after the paste.  This makes significant performance
impact.

Change-Id: Ic4f7d7b2fe152bd5640ddb1dae01cc2ed757657e
(cherry picked from commit 808fd5fbd8868dfd95c8a38676815798fa2b79c4)