relabeled Maps to Visualizations
reordered maps and updated better descriptive text in Visualizations menus
updated quick tutorial map
cleanup menus layout, updated quick guide
cleanup data model (now databases) menu, and presentation of items, added web service api links
added feedback on gene add, new genes added to top of list
added feedback on clinical variable add, new variables added to top of list
Merge pull request #37 from hrovira/ux_updates_01

updates in response to UX design feedback