fsmonitor--daemon: on macOS support symlink

Resolves a problem where symbolic links were not showing up in diff when created or modified. kFSEventStreamEventFlagItemIsSymlink is also treated as a file update. This is because kFSEventStreamEventFlagItemIsFile is not included in FSEvents when creating or deleting symbolic links. For example: $ ln -snf t test fsevent: '/path/to/dir/test', flags=0x40100 ItemCreated|ItemIsSymlink| $ ln -snf ci test fsevent: '/path/to/dir/test', flags=0x40200 ItemIsSymlink|ItemRemoved| fsevent: '/path/to/dir/test', flags=0x40100 ItemCreated|ItemIsSymlink| Signed-off-by: srz_zumix <zumix.cpp@gmail.com> Signed-off-by: Taylor Blau <me@ttaylorr.com>