Log Message:
Update ruby-mime-types to 1.18.

== MIME::Types 1.18 / 2012-03-20
* New MIME Types:
  * Types reported in Issue #6
    (https://github.com/halostatue/mime-types/issues/6):
    * CoffeeScript (text/x-coffeescript; .coffee; 8bit).
    * AIR
      (application/vnd.adobe.air-applicationinstaller-package+zip, .air;
      base64).
    * WOFF (application/font-woff; .woff; base64).
    * TrueType (application/x-font-truetype; .ttf; base64).
    * OpenType (application/x-font-opentype; .otf; base64).
  * WebM (audio/webm, video/webm; .webm). Issue #11
    (https://github.com/halostatue/mime-types/issues/11).
* New extensions:
  * f4v/f4p (video/mp4, used by Adobe); f4a/fb4 (audio/mp4, used by Adobe).
* Bug Fixes:
  * It was pointed out that Licence.txt was incorrectly named. Fixed by
    renaming to Licence.rdoc (from Issue/Pull Request #8,
    https://github.com/halostatue/mime-types/issues/8).
  * It was pointed out that a plan to have the test output generated
    automatically never went through. Issue #10
    (https://github.com/halostatue/mime-types/issues/10)