Adding custom exceptions
adding inner exceptions to thrown ones
Only turn off endpoint validation for known test endpoints
Manually managing token refreshes
Merge pull request #1952 from christav/exceptions-296

Rework for AD logic
Filter out subscriptions that haven't been backfilled yet
Merge pull request #1955 from christav/filter-backfill

Filter out subscriptions that haven't been backfilled yet
Merge branch 'dev' of https://github.com/WindowsAzure/azure-sdk-tools into azurert-sm-integration