added enable_new_users setting, default true
added form item and strong params
fixed .env comment
checked for user creation flag in controller
made UI registration elements dependent on flag
fixed Rails Admin weirdness
added some tests
removed category destroy link
removed equipment model destroy link
removed user destroy link
removed sidebar layout from reservations controller
updated reservation#show view for full width
updated Reservation#renew to log renewal
actually increment times_renewed
Merge pull request #1047 from YaleSTC/957_scaffold_links

#957 Remove Scaffold Links
fixed nil errors
started using CanCanCan for ability
fixed specs
took out meaningless before_action
updated abilities to account for quick create modal