Make BfPixelBufferTest resilient to remoting.
Merge pull request #1597 from bpindelski/rebased/develop/11480-remoting

Make BfPixelBufferTest run against a remote server. (rebased onto develop)
Change assertions semi-automatically.
Further manual changes to assertions
Use pytest idiom to assert exceptions.
Remove self.fail in favour of assert False.

And fix one missed exception handling case.
Remove erroneous test file.
Fix various imports and remove unittest from all test files.
test_client_ctors is a special case that doesn't use lib.ITest
Switch the library from unittest to pytest.
Override setup in imetadata test.
Expose tests in annotationPermissions and override fixtures.
Change tests in subdirectories to pytest.
Fix make movie test.
Move table tests to pytest.
Remove unecessary output from bigImages test and use assertion.
Change missed assertEquals
Modify thumbnail perms tests to resolve conflicts.
Change assertTrue to assert in recently added test.
Switch unit tests to use pytest idioms throughout.