Pull volunteer out to button

By Mollie's suggestion, make 'Volunteer' a button at the bottom
of the opportunity list.  Make it a call to action.

Also change "owner" to "requestor".
Add ModalAlert comp; add volunteer dialog

By having a standardized alert component, can pop up
a modal for verifying things with the user (otherwise
known as "are you sure?" dialogs).  Implement it for
volunteers, so that they have to confirm they have
supervisory approval.

Addresses issue #65.

Puts in the framework for issue #84.
Add "are you sure" for close proj/opp

This addresses issue #84 and prevents
accidental closures.
Fix project cards to show counts

Fix issue #100 with an absolutely positioned
div that puts the counts at the bottom of the card.
Combine 'are you sure' work with registration app

Merge branch 'sprint10-feature-areyousure' into sprint10-feature-register