Possible fix for precompiling assets on Heroku
Moves fix to application.rb?
Removes debug message
Refactors get_valid_project to use one less sql query
Rearranges sidebar on views

Sidebar is placed by each view inside their sections, rather than outside by the
application layout, so that the section items can flow around it. Forms
especially got reworked to sit nicely next to it.

Also, buttons and fake buttons get their styles from .button-link class.
I banish thee, N+1 query.
Updates much of the layout

Controllers no longer use render when redirect would work (except user for now).
The flash is used to pass messages between requests, and forms have been changed
accordingly to display them.

Header and nav bar have their own css files now.

The nav bar (parent_bar partial) changed to have more logical flow. A wrapper
the width of the sidebar sits on the left, and two link tabs float left and
right within it. The wrapper pushes the item/parent thumbnail tabs to their
proper locations.

The header also is now starting to be properly arranged.
Updates UserController's views

Root and UserController now redirect rather than render. When not logged in,
the sidebar changes to a sign-in form, with a sign-up link below that.

Sign-up is still not styled.
Markdown madness

Adds the Redcarpet markdown parser. Redcarpet loads a parser from a the
load_parser method in ApplicationController. Controllers call it in a
before_filter on any views that could display text. (Would like to determine
if it's possible to keep the parser initialized constantly.)

Item#get_content requires the parser to be passed into it in order for it
to call render. It does this so that it can internally escape any html before
sending the markdown to the parser. (The output has to be marked html_safe.)

Parsed text appears in an item's show page, as well as any previews or any
previews or thumbnails of items. The css selectors .text-content, .item-preview,
and .item-thumbnail have their own styles. The content can have h1-h3 in it.
Merge branch 'master' into aws