refactor to pass regression tests
begin adding availability grid
add specs for shift grid
add availability grid
add color coding to avail grid
Refactor shift grid to use grid.rb
write passing specs for avail grid
add sorting to avail grid
add avail dropdown to nav bar
add edit links to avail grid (with redirect links back to avail grid)
clean up avail grid links
add sort to shit grid
add prototype calendar datepicker to avail grid filter
add calendar datepicker to grid filters
Refactor datepicker into partial
adapt grid specs for new datepicker, add specs for grid links
tweak grid specs (for new datepicker)