Huge monsters easily climb out of pits

Also, give a message when a monster trapped in a pit, a web,
or a bear trap frees itself.

doc/fixes3-7-0.txt

@@ -809,6 +809,8 @@ elves and rangers get alignment penalty for cutting down trees
 casting a forgotten spell uses some random amount of power
 heroes starting with a spell have at least one level one spell, and
 	have just enough power to cast it
+huge monsters get easily out of pits
+give a message when a trapped monster frees itself from some trap
 
 
 Fixes to 3.7.0-x Problems that Were Exposed Via git Repository