Limit scope of icon CSS wildcards to icon-spree-

The existing "icon-" wildcards wound up blowing up all of my font awesome stuff in my existing store.  I 'fixed' it locally by cloning this file and changing like 23 to "icon-spree-".  I feel like this is maybe a useful addition to everyone and not just for me.

Thanks for the addon!

Fixes #134
Instructions for creating an initializer

Adds instructions for adding an intitalizer to bootstrap an oAuth service on application boot. Useful to not have to recreate Authentication Methods when deploying new environments or between truncating / db dump/loads between production and staging.
Merge pull request #138 from j-mcnally/master

Instructions for creating an initializer
Spree master is now 2.4.0.beta