Added Xrm.Page API for Microsoft Dynamics CRM

Recreated pull request to resolve a curious "conflict" of edits that doesn't appear to actually exist.
I've been using some form of a TypeScript definition file for Microsoft Dynamics CRM for 2 years. In order to encourage more Dynamics CRM developers to seriously consider TypeScript as a preferable language to hook into its UI's extensibility model, I've completely done up these definition files from scratch, and liberally applied code documentation, which borrows heavily from the Microsoft's own API documentation, to ensure a high-quality experience. Once the pull is accepted, I'm ready to go-live with a blog posting at crmentropy.blogspot.com that highlights some of the conventions I've taken with the definition (particularly around the use of Generics).