* FIX: Hide tag watched words if tagging is disabled
These 'autotag' words were shown even if tagging was disabled.
* FIX: Make autotag watched words case insensitive
This commit also fixes the bug when no tag was applied if no other tag
was already present.
This reduces chances of errors where consumers of strings mutate inputs
and reduces memory usage of the app.
Test suite passes now, but there may be some stuff left, so we will run
a few sites on a branch prior to merging
