Document how `core.fsmonitor` can be set to a boolean to enable
or disable the builtin FSMonitor.
Update references to `core.fsmonitor` and `core.fsmonitorHookVersion` and
pointers to `Watchman` to refer to it.
Create `git-fsmonitor--daemon` manual page and describe its features.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
