hookup_manager stage one:  New tables for pending and active hookups (pair programming events)

relates to pivotal stories "display list of pending events in a table", 75025008, and "display list of active/live hookups (i.e. hookups with live hangouts) in a separate table",75025492. 
I think that these comments are important because they point out the limitations/problems of the function given the current schema/data structures.  Eventually, I hope that we can add/modify the schema to remove these limitations.