Added test for bad modified date.
Added test for bad modified date.

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