Merge pull request #32 from WindowsAzure/dev

2.4.0.0
Remove Live related stuff.
Merge pull request #34 from ivan-shaporov/master

Remove Live related stuff.
Add content key authorization policy.
Fixing Queryable assignment that has been lost. + A workarounf for unit test.
Merge from public dev.
Merge pull request #1 from ivan-shaporov/dev

Add content key authorization policy option.
Return Task with correct generic parameter from async methods.
Merge pull request #2 from ivan-shaporov/dev

Return Task with correct generic parameter from async methods.
Adding the ability to create EnvelopeEncryption content keys
Adding ContentKey Authorization policies
Merge pull request #36 from ivan-shaporov/dev

Avoid double querying of created asset file.
Merge pull request #37 from ivan-shaporov/dev

Avoid unnecessary REST requests upon uploading and updating asset files.
Wrap DataServiceContext into MediaDataServiceContext.
Merge pull request #6 from ivan-shaporov/dev

Wrap DataServiceContext into MediaDataServiceContext.
Create retry policies. Wrap DataServiceResponse.
Add license headers.
Merge branch 'dev' of https://github.com/WindowsAzure/azure-sdk-for-media-services-pr into dev
Merge branch 'dev' of https://github.com/ivan-shaporov/azure-sdk-for-media-services-pr-personal into dev.