Add support for WP8.1
Merge branch 'dev' of github.com:Azure/azure-sdk-for-net into dev
Refactoring on update of supporting WP8.1
Merge pull request #717 from ljhljh235/dev

Add support for WP8.1
Fix Extension Image Register API
add new file
Merge branch 'dev' of https://github.com/Azure/azure-sdk-for-net into dev1
Merge pull request #726 from huangpf/dev1

Fix Extension Image Register API
Merge pull request #727 from Azure/dev

Merge dev to master