Microsoft MT Connector: Datamarket authentication is being end-of-lifed

[Chase Tingley]

See: https://translatorbusiness.uservoice.com/knowledgebase/articles/1078534-microsoft-translator-on-azure

Background: MS Translator API access is split between two platforms. Authentication is done against the Datamarket service, which produces an access token that can be used for real API calls. It sounds like the Datamarket stuff is being retired, and we will need to authenticate against a different API:

Your current Microsoft Translator API subscription on the Microsoft DataMarket will continue through December 31, 2016, with full subscription functionality

Service access on Microsoft DataMarket will be limited to the monthly volume plan subscribed, beginning January 1, 2017

Remaining Microsoft Translator API subscriptions will be canceled on April 30, 2017

The linked article doesn't currently say what the new authentication platform will be, but our connector will need to be updated to handle it when it becomes available.

[Chase Tingley]

Fix issue #566: Microsoft MT Connector: switch to Azure authentication

WARNING: This *breaks* legacy support for
clientId/clientSecret-based authentication.  You will need to
migrate to an Azure-based subscription in order to use this code.
See https://translatorbusiness.uservoice.com/knowledgebase/articles/1078534-microsoft-translator-on-azure

→ <<cset 164fc57c365b>>