The newer version of FUSE_INIT checks the response from the FUSE server
if its major number is equal to 7. If it's not, then FUSE_INIT fails and
further filesystem operations will get ECONNREFUSED. To mitigate this
issue, we can send back a response with major version equals to 7 when
consuming the first FUSE_INIT request.
Fixes#3500
This commit adds an integration test framework for FUSE support. Please
refer to the test example and test/fuse/README.md for further details.
Fixes#3098
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Craig Chi