Fix crash when clicking the preview icon.

For some reason the NSPanel was autoreleased after being loaded from the
nib. Fixed it by using `[NSWindowController initWithWindowNibName:]` instead
of loading the nib by hand in `mainWindowInBundle:`.
Upgrade PluginWindow.xib to Xcode 5 format

Note that this will prevent the xib to be edited in Xcode 4.x
Link the window outlet the file's owner (ATZPluginWindowController)
Merge pull request #80 from guillaume-algis/issue79-preview-icon-crash

Fix crash when clicking the preview icon. - Related to issue #79
Update README.md
Update .gitignore with new Xcode5 files
cleaned some tests
cleaned up some unused stuff
added some resources. pretty broken atm.
fixed resources
Removed GC flag
replaced default horizontal lines with fabio's idea. constraints are screwed up
fixed constraints a little bit. still not perfetto
made horizontal lines .5 alpha
fixed more constraints
fixed all the constraints conflicts
wired back buttons and search field
moved notifications from installer to controller. only displayed if window is not focused
Delete Alcatraz.xccheckout. Related to PR #82.

Remove the Alcatraz.xccheckout file from the repository as it produces noise each time a PR is merged and is now ignored by git since PR #82.
Important note: This will also delete your local Alcatraz.xccheckout file upon pull. Make a backup! ;)
update podfile to cocoapods v 0.27.1