Media grid delete

Hopefully everything is self contained here.  I tried to split up the commits up into manageable chunks.  Still getting the workflow down.  Let me know if there is anything I can do differently.

So user can now select all items on page, or just certain items on page, and delete from a popup that fades in towards bottom of screen (the old .selected-media-details that was commented out but is now much more streamlined).  Clicking on delete icon asks for confirmation than on acceptance sends via ajax to php which calls wp_delete_attachment (which I am assuming is the right way?).  User can also just delete per item which does the same thing.  I have added some user feedback as far as how many items in total vs how many items are viewable (thought it was important for the check-all scenario) vs how many items have been selected (shows up in the selected media popup).