Fixed bug where PushServiceSettings could be null

Also fixes a possible unhandled error from APNS feedback service
NuGet 1.0.5
Started Windows 8 Support
Update master
More work...
Windows Push Channel Roughly implemented
Windows Push work, basics should be working!
Fixeds #18
Closes #17
Fixes #16
Fixes #12
Fixes #13
Closes #19

Manually merged the ideas in Pull Request #19
Bumped version and released new NuGet package
Fixes a minor bug in the original fix for #13
Bump version and new NuGet package
Allow usage of an already existing X509Certificate2 object for the channel settings for Apple.
Avoid adding aps key if it is empty.
Merge pull request #21 from ibauersachs/master

Certificate handling enhancement
Fixes #22