Fixed and re-enabled rewritten version of filling points in possession mode.

git-svn-id: http://keeperfx.googlecode.com/svn/trunk@1421 40a56aae-0377-11df-bfb3-7781b9cb07ea
Modified possession to be only available when player has the spell.

git-svn-id: http://keeperfx.googlecode.com/svn/trunk@1422 40a56aae-0377-11df-bfb3-7781b9cb07ea