Converted project to a Portable Class Library.

Converted project to a Portable Class Library supporting .NET 4, Silverlight 5, Windows 8.x, and Windows Phone 8

- TitleInfo.ToTitleCase() is not supported on PCLs. An alternative will
need to be found.
- The "Localizable" attribute is not supported in PCLs. The impact will
need to be researched.
- The "DescriptionAttribute" is not supported in PCLs. An alternative
may need to be found, if necessary.
- The NuGet package process will need to be altered.
- All issues found in the code are marked with //TODOs