Merge pull request #1 from sebabelmar/SETUPS

Setups
adds UsersHelper
updates user model w/ #search and #offer (as calendar route)
updates user#index view: link to #offer and #search views;list of active friends of user; WIP - adds empty views for #offer and #search
adds routes: users#search and users#offer as calendar
Merge pull request #2 from sebabelmar/user

User
Merge branch 'master' of https://github.com/sebabelmar/sitter into Timeslots
add timeslot new views