Promise support for geoNear

added promise support for geoNear & accompanying tests #1614
geoSearch promise support; refactoring of tests

geoSearch & geoNear tests refactored. Additionally, callbacks now have
appropriate parameters based on the API. Seeing weird things happen in
the tests like failed assertions not happening, ect. Also, the 2.4 check
isn't working for some reason. Before() doesn't happen
refactoring tests on geoSearch