migrated to md5 2.x

[javascriptlove]

MD5 is too old, and there are issues with running on meteor 1.3 because other packages need 2.x. Getting errors like this on linux:

While building the application:
   packages/andrefgneves:iconfont/plugin/iconfont.coffee:67:24: undefined is
   not a function (compiling
   node_modules/materialize-css/dist/font/material-design-icons/Material-Design-Icons.svg)
   at generateCacheChecksum
   (packages/andrefgneves:iconfont/plugin/iconfont.coffee:67:24)
   at didInvalidateCache
   (packages/andrefgneves:iconfont/plugin/iconfont.coffee:53:24)
   at handler (packages/andrefgneves:iconfont/plugin/iconfont.coffee:42:8)
...

   While loading plugin `andrefgneves:iconfont` from package
   `andrefgneves:iconfont`:
   error: Can't load npm module 'MD5' from
   packages/andrefgneves_iconfont_plugin.js. Check your Npm.depends().

[javascriptlove]

Also, please push this to atmosphere