Added WP8 libary with podio model classes

Added a WP8 library to the project. Also updated the program.cs file in the convert ruby models to auto create the WP8 model classes based on the ruby model. Last chage was adding a new config item on the app.config.sample for the newly created window phone 8 library.

FYI, this pull request should only have the updates, not like previous where it seemed to have touched the entire solution.

ping me on here or @johnmcbride on twitter :)