Added development scripts

You should pull these in when you get a chance, this is the full fledged scripting that you asked for. Here is the quick lowdown of what everything is:
**dist** - does everything, takes version number from VERSION in root (uses **new**, **reversion**, **buildjs**, **package**)
**new** - creates a new cordova-wp7 repo in the specified directory
**reversion** - deletes any generated files (including .dll, CordovaDeploy.exe, and all cordova.js files) and reversions the repo and rebuilds .dll (does not rebuild CordovaDeploy.exe).
**buildjs** - grabs the specified (or if none specified, grabs VERSION) js from git, builds it and copies to correct locations.
**package** - builds templates
**deploy** - builds CordovaDeploy.exe if not already built and deploys to the specified location (called from emulate or debug)
**build** - builds the .xap for the project in the specified folder (not used by any other scripts)