user can add new user and family for a player
minor updates to addUser view and funciton in players.js, adds user_added_for_player mailer
adds email notifications to the added family for player controller action
fixes a lot of reference errors in user_added_for_player mailer
successfully sends reminder emails to every parent in the individual reminder button
upgrades to rsvp_mailer, now has descriptive email body
checks that a family does not already exist before creating a new one in addUser
adds error message if an email is already associated with a player
Merge branch 'master' into egan-dev
adding family add and email features to recent updates
Merge pull request #36 from AEgan/egan-dev

users can create new family for player + updates