Adds support for 'Open in "Vim"' (fix #12, fix #6)

 * Adds application:openURL:sourceApplication:annotation: method, code
   written by @N-Holzschuch (see issue #12)
 * Adds CFBundleDocumentTypes to Info.plist. This only covers the types
   that Apple already knows about. I found that *.md was not recognised
   and niether was Makefile (not sure what to do about that one).
 * Adds images for document icons. In my tests only *.plist files used
   this icon (Pages seems to take over). The iPad images are slightly
   offset so that the corner page curl doesn't obsure the logo.
Copy Exported UTIs from MacVim

Note that that these are only a small selection of the 400+ file types
that are mentioned in vim's syntax files.
Fix #14 Partially draw screen on update
Fix #15 Update the whole scrolling area
Merge remote-tracking branch 'refs/remotes/applidium/master'
Added a default iPhone 5 image (With uppercase)