Apply pyfmt to fbcode long tail 7/7
Apply pyfmt to fbcode long tail 7/7

Summary:
Formats a subset of opted-in Python files in fbsource.
Black formatting was applied first, which is guaranteed
safe as the AST will not have changed during formatting.
Pyfmt was then run, which also includes import sorting.
The changes from isort were manually reviewed, and
some potentially dangerous changes were reverted,
and the `# isort:skip_file` directive was added to those
files. A final run of pyfmt shows no more changes to
be applied.

Reviewed By: zertosh

Differential Revision: D24151644

fbshipit-source-id: cd3a71876696bd438d38285d8e7856d05f888814

facebook/watchman,nodakai/watchman,facebook/watchman,nodakai/watchman,nodakai/watchman,facebook/watchman,nodakai/watchman,nodakai/watchman,facebook/watchman,facebook/watchman,nodakai/watchman,facebook/watchman,facebook/watchman,nodakai/watchman,facebook/watchman,facebook/watchman,nodakai/watchman,nodakai/watchman