#6 Build script for Femah and #7 Publish Femah as a NuGet.org package

#6 Build script for Femah and #7 Publish Femah as a NuGet.org package
Added automated build scripting that..
- Cleans build folders
- Generates a consistent version number
- Compiles
- Executes NUnit unit tests
- Creates versioned (prerelease) Femah.Core NuGet package