Issue #24 - First attempt at common version

- This is the first attempt to use a common version number for all
projects, msi, and nuget packages.  Won't be able to test this properly
until all tests pass.
- Updated gitignore file to not check in BuildArtefacts
- Updated projects to use CommonAssemblyVersion and CommonWixInfo files
- Added psake build scripts
- Added build.bat file that will be used by MyGet Build Services