Changes description included in the README file
The required NuGet packages are now explicitly referenced from the project file

That way we'll be able to generate the nuget package dependencies automatically from the project file
The AssemblyInfo includes Desription shared with the NuGet Package description and explicit InformationVersion
The default build configuration is Release now

This will be required so that we can integrate with the MSBuild and Nuget substitution
The DLL is published under lib/net40 but was built as .net 4.5
#DRY Removed duplication between the rakefile and assembly information

The id, version and description are now extracted from the assembly information by nuget
This required moving nuspec next to the project file.
Also some relevant tags are added so that it's easier to find the package in NuGet Gallery
NuGet.exe now at version 2.7
Merge pull request #2 from mfloryan/build

Tidy-up and dry out the build process