Add user can view and update posts
Add view and edit links for current_user
Remove sign-in check from edit post form

The edit post form won't appear at all unless the user is signed in and
is the owner of the post (the controller grabs the post from
current_user).

Also removed blank lines after the end of the post show page.
Restore location_id - post index collection_select

switching broke the ability to save posts.
Reordered methods in controller after rebase
Remove duplicate  post titles in posts list

The rebase resulted in duplicate lists for the all posts list. Combined the two
into one.
Remove skip from before action
Add null object method for posts

Added null object for posts, added null object for post ids, added
before action to redirect attempts to edit other people's posts, hid button
for post editing if you're not the post's owner.
Fix extra space in posts controller
Improve robustness: null post, null id

Changed empty array to Post.none for null post
Changed false to -1 for null id
Fix space error in post form, remove test text

Removed the login info text in the posts index.
Added missing space after name in collection select.
Merge branch 'lea-users-can-view-posts'

* lea-users-can-view-posts: (53 commits)
  Fix space error in post form, remove test text
  Improve robustness: null post, null id
  Fix extra space in posts controller
  Add null object method for posts
  Remove skip from before action
  Remove duplicate  post titles in posts list
  Reordered methods in controller after rebase
  Restore location_id - post index collection_select
  Remove sign-in check from edit post form
  Add view and edit links for current_user
  Add user can view and update posts
  Remove unnecessary horizontal spacing around form
  Extract form elements to render as a partial
  Validate presence for post in PostCategory mod
  Fix spacing error in migration file
  Remove empty array from post params
  Collection check boxes post correctly
  Change Post Category model to validate presense
  Modify models to correct table name PostCategory
  Change collection select to collection checkboxes
  ...
Minor modifications to make locations validate name
Nest categories in locations and let admins create
nests post.create under locations
Render errors if post form doesn not save