In 8a0775ce3c which was released in v1.49.0 we inadvertently
stopped SAS URLs working from the root without a container name.
Previously to this change you could use `rclone mount azsas:` and it
would actually be equivalent to `rclone mount azsas:container`. After
this change, only `rclone mount azsas:container` will work, `rclone
mount azsas:` will have a directory in the root called "container".
After some discussion it was decided not to revert this change as the
current behaviour is more logical and in line with the similar
behaviour for the b2 backend.
Instead the documentation was updated to show exactly how container
level SAS URLs behave.
Fixes#4028
* azureblob - Add support for Azure Storage Emulator to test things locally.
Testing - Verified changes by testing manually.
* docs: update azureblob docs to reflect support of storage emulator
This change includes removing older azureblob storage SDK, and getting
parity to existing code with latest blob storage SDK.
This change is also pre-req for addressing #2091
* Fixup bitrot (rclone and Azure library)
* Implement Copy
* Add modtime to metadata under mtime key as RFC3339Nano
* Make multipart upload work
* Make it pass the integration tests
* Fix uploading of zero length blobs
* Rename to azureblob as it seems likely we will do azurefile
* Add docs