Added Microsoft.Bcl.Async dependency in WP7 to support async
Added Microsoft.Bcl.Async package dependency to nuspec for WP7
Moved Services that can be used in background agents into a separate project
Ensure that Microsoft.Bcl.Async assemblies are excluded from WP7 projects output
Added project references to Background projects for main toolkit

These will need to be changed to nuget references when the Background
project is up.
More changes for Background Task support
Merge branch 'master' of https://github.com/ScottIsAFool/Cimbalino-Phone-Toolkit into ScottIsAFool-master
General refactoring on Cimbalino.Phone.Toolkit.Background project
Updated NuGet
Moved IDeviceStatusService to Cimbalino.Phone.Toolkit.Background project
Moved the TableObject class to Cimbalino.Phone.Toolkit.Background
Move the IDeviceStatusWith.IsKeyboardPresent implementation back to Cimbalino.Phone.Toolkit
Moved a bunch of classes to Cimbalino.Phone.Toolkit.Background