[MlMt] Missing items on hidden prefs webpage

[Antonio Leding]

Hello all,

I am discovering at least a couple hidden preferences are not described 
on the actual hidden prefs webpage.  Is this expected?  Or have some of 
these hidden preferences become unhidden?

The ones in particular I am concerned with right now are 
“MmDeleteBehavior” and “MmAutomaticExpungeBehavior” - neither 
are on the hidden prefs webpage…