Interface suggestions from a pro

[izaslavsky]

1. remove file name from the upper left, before the count (not needed on the interface)
2. make search box more prominent, and centered in the facet panel (now it is left-justified)
3. showing "searching for.." or something like that when only a subset of variables is shown
4. make facets expandable to the right
5. there is too much white space under expanded facets - that space is unused
6. ability to change background color would be nice
7. make sure there are no console errors (now they show up quite regularly)