New WP8 Tile Templates, and XML to Linq'ified

Also Fixes #7 finally (Manually merged changes)
Made GCM Client more friendly

Refactored/Renamed some things to make the GCM Client (PushClient for
Mono for Android) easier to implement and understand, using some new
features in Mono for Android (such as the [Permission] and
[UsesPermission] attributes)...
Update README.md
Update README.md
Update README.md
Changes to fix the recent WP8 tile additions

1. Added nuget restore to the project so it will build outright on a
fresh pull
2. All three new tiles had been given the template "FlipTile",
corrected.
3. Nearly all three new tiles' xml wasn't being created because it was
just checking whether the Title property had a value, rather than the
correct property
4. New tiles were missing the TileId property
Merge pull request #86 from ScottIsAFool/master

Changes made to fix bugs in the new WP8 tile notifications.
Testing a fix for #85
Improved Windows 8 Notifications
Windows Notification Fixes

Made Branding an enum.
Windows 8 Notifications

Changed how Windows 8 Notifications are built, which overcomes the
limitation of Tile notifications only allowing a single binding.  Now
many bindings are allowed, however it's up to the user to make sure a
correct combination is used.
Another test fix for #85
Windows 8 minor fixes
Added WithTimeToLive method
Merge branch 'master' of https://github.com/Redth/PushSharp
Merged conflicts