Squashed 'Telerik.Sitefinity.Samples.Common/' changes from 0f1e27d..8e98e2b

8e98e2b Merge commit '3d36553dfecf0102f17289986822c7d9e684a115' into HEAD
3d36553 Upgraded to Sitefinity 7.3.5600.0
5efcd44 Update README.md

git-subtree-dir: Telerik.Sitefinity.Samples.Common
git-subtree-split: 8e98e2b7fc2ee85df65d4143ebb1d338c1aa6aa2
Merge commit '4ac171edc80a9a6539a7451aee693d372a6809ce' into review
Upgraded to Sitefinity 7.3.5600.0
Fixed obsolete errors in Book.cs
Enabled RestorePackages in NuGet.targets
Merge commit '88501387e9d25d571f55580e426f93139556a944' into HEAD