monsters with MH_PLANT holiness to be polymorphed, so that they can still be handled quietly. Note that, according to the rules of polymorphing, they can only be turned into monsters of the same holiness that give experience when killed. This means that giant spores, wandering mushrooms, and oklob plants can now be quietly polymorphed into each other.

git-svn-id: https://crawl-ref.svn.sourceforge.net/svnroot/crawl-ref/trunk@9055 c06c8d41-db1a-0410-9941-cceddc491573