Merge branch 'kw/fsmonitor-watchman-racefix'

A new version of fsmonitor-watchman hook has been introduced, to avoid races. * kw/fsmonitor-watchman-racefix: fsmonitor: update documentation for hook version and watchman hooks fsmonitor: add fsmonitor hook scripts for version 2 fsmonitor: handle version 2 of the hooks that will use opaque token fsmonitor: change last update timestamp on the index_state to opaque token