* Move UserAgentGenerator to _internal
* Clang-format
* Update release date to November release (Core)
* Update release date to November release (EventHubs)
* _MSVC_LANG
* Move comment up
* Add /Zc:__cplusplus when building the SDK, and add unittest
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Co-authored-by: Anton Kolesnyk <antkmsft@users.noreply.github.com>