[chore] Updated tooltip to use ui-popover

Updated tooltip to use angular-bootstrap component
- tooltip just adds circle_question_mark classes
- use popover directive directly
- tooltip renamed to rv-tooltip because of conflict with ui-bootstrap name
Updated tooltip demo page

Updated Column Selector title to use standard label
Updated Scroll Setting tooltip and column widths
Merge pull request #106 from alex-deaconu/master

[chore] Updated tooltip to use ui-popover