Column header tooltips

[justinbmeyer]

For each column, it would be nice to include a tooltip describing what that column represents and how it's calculated.

For example:

• Significance - A number between 0-100 on how critical an OS project is to an average client project and how significant it is to Bitovi. The OS core team sets these numbers. Blah Blah Blah.

Ideally, this should link back to the royalties document.

[jamiemccue]

• Add Bootstrap Popovers on column headings
• Popovers allow for more text than tooltips
• Add popover definitions for each column heading
• Consider a dashed underline (or abbr) to indicate the popover.

[jamiemccue]

@justinbmeyer is this issue complete or still in progress?