Standardized NAnt script

Updated NAnt build files to 2.6.2
Removed CommonAssemblyInfo.cs
Updated various dependencies
Now targeting .NET Framework 4.5
Deleted unnecessary build-related files
Enabled NuGet package restore
Updated NuGet to 2.2.1
Updated NUnit to 2.6.2
Updated JuniorRoute to 3.0.0
Removed all XML documentation
EmailSender is now asynchronous
Excluded NuGet packages folder