Squashed 'Telerik.Sitefinity.Samples.Common/' changes from a17eb52..67ef4a3

67ef4a3 Updated references to point the packages for SF 7.1.5200.0 (Official release)
48983d1 Upgraded to SF 7.1.5200 (Official release)
2eb2bb8 Updated references
c1961d3 Fixed blog posts duplicate creation on system restart
74d36c5 Upgraded to Beta HF 1 (7.1.5141.0)
bcb289e Changed the check for existing thread
6d0290e Updated hintpaths
f049418 Updated import directive condition
52b0011 Merge branch 'review' of https://github.com/Sitefinity-SDK/Telerik.Sitefinity.Samples.Common.git
fc3bd09 Updated versions when SitefinityWebApp condition
91cbdc9 Updated .csproj improt StyleCop condition
05b3b74 Upgrade to Sitefinity 7.1 Beta

git-subtree-dir: Telerik.Sitefinity.Samples.Common
git-subtree-split: 67ef4a3441bfce08f252351ab0cc02b3144a9560
Merge commit '53b536186fbe116aa202861ba9899e3ee5d7949b' into review