Added F# specific NUnit project

This project doesn’t use the codedom and produces code which look nicer
than the codedom output.  Also addresses an existing bug that tries to
open a C# specific file in the template.
Added F# specific NUnit Test Fixture file template
Updated template name, removed explicit filename
Merge pull request #403 from 7sharp9/AddFsharpSpecificNUnitProject

Added F# specific NUnit project and file template