HUE-2255 [fb] Drag and drop a file directly into the page

Added test to ensure dropped item is file prior to showing upload progress
[fb] Visual hint for global upload progress

Added mini upload progress bar at the bottom of the page
HUE-2253 [fb] Simpler bottom bar

Implemented 'skipTo' method for pagination
Implmented updated navigation buttons and input to skip to a particular page
Moved styles from fb.css to display.css for display.mako specific files
Moved fb.css to listdir_components.css for listdir_components.mako specific styles