watchman-4.7.0-bp151.2.12

- fallthrough.diff: fix gcc 7 build issues

- Replace %jobs by %_smp_mflags; drop unnecessary %clean section.
- Avoid multiple invocation of %service_*.

- added subpackage for python bindings
- added systemd unit files for service and socket for inetd style spawning of
  watchman user instances via systemd

- initial version using the buildservice
- no support for systemd, python or ruby bindings yet