Merge pull request #12 from daf-/shift

Many updates to shift.
put shifts in coop for routing
only admin can create recurring meals and shifts in coop. begin making html forms for meal/shift creation
Only let users edit their own coop.
See shift info on all coop pages.
form for creating meals
form to add meals with shifts to coop
begin working on meal and shift creation from meal form
meals are created via new form system. join table in preparation for creating the associated shifts
shifts are created for new meals. existing shifts are updated to refer to the new meals. if meal no longer occurs on a day, its shifts are destroyed.
Merge pull request #13 from daf-/only-edit-own-coop

Only let users edit their own coop.
Merge branch 'master' of https://github.com/daf-/coop-site into admin-creates-all-shifts

Conflicts:
	app/views/coops/show.html.erb
put shifts in user show. only same user can see their 'show' page.
user can select their shifts
fix meal info display
add global links
user can have phone and pic.
user can mark whether or not to display email and phone
user can destroy their account
username is 'required' (there are still some loopholes)
nav links are hidden on edit user page when the user doesn't have a username (when user first creates account)
selected tab appears differently. users shifts appear (not correctly) in calendar view
show shifts on user shift page. user can click shifts to see who is in them. emails and phones are shown for users that have elected to share this info
keep track of last user to edit a meal and display username of editor in meal info