Better error reporting in assertAction.
Better error reporting in assertAction.

jeffmahoney/supybot,mazaclub/mazabot-core,mazaclub/mazabot-core,buildbot/supybot,Ban3/Limnoria,kblin/supybot-gsoc,Ban3/Limnoria,ProgVal/Limnoria-test,raboof/supybot,haxwithaxe/supybot,frumiousbandersnatch/supybot-code,prashantpawar/supybot-rothbot,ProgVal/Limnoria-test