Added NuGet package generation files

I added a script, dependent assemblies, and spec files to generate a NuGet package for this project. The package can be seen at https://nuget.org/packages/Bootstrap.DateTimePicker/0.0.20130428. I would be happy to transfer ownership of this package.

As a side note, I'm currently using the date (YYYYMMDD) in the **Patch** portion of the version number because there doesn't seem to be any official version number on the project.