Implemented 4 new widget positions for Showcase Index and Category pages

I've added 2 new Widget Positions to display widgets below the Items list on Index & Category pages.

I've also added 2 new Widget Positions to display widgets in the sideBAR on Showcase Index and Category pages. Please note that Showcase uses the sideNAV (which is on the left hand side of the page) and does require editing templates to fully remove the sideNAV from SC Index and Category pages. Keep that in mind if you add any widgets to the sideBAR (as you will end up with a 3 column layout if you don't remove the sideNAV code for the Navigation sidebar block).