Use Select2 to improve Generation Forms #13

I think we should use Select2 to allow tag-like input for all the fields that will allow more than 1 input.

There are quite a few items that would fit that profile, but as of right now I'm providing a list of the one I think could be implemented for v0.1.2.

Items

• Taxonomies select on Terms
• Terms selection on Posts
• Select Post Types
• Roles for users