pull from master into dev

<a href='#crh-start'></a><a href='#crh-data-%7B%7D'></a>
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<a href='https://www.codereviewhub.com/AzureAD/azure-activedirectory-library-for-objc/pull/239?approve=1'><img src='http://www.codereviewhub.com/site/github-approve.png' height=26></a>&nbsp;<a href='https://github.com/AzureAD/azure-activedirectory-library-for-objc/pull/239'><img src='http://www.codereviewhub.com/site/github-refresh.png' height=26></a>
<a href='#crh-end'></a>