Need to catch the kFSEventStreamEventFlagUserDropped on Mac

[michilu]

The kFSEventStreamEventFlagUserDropped ( 0x00000002 ) is thrown frequently in Mac environments.

It is thrown only kFSEventStreamEventFlagUserDropped when update the file.

see kFSEventStreamEventFlagUserDropped

The kFSEventStreamEventFlagUserDropped or kFSEventStreamEventFlagKernelDropped flags may be set in addition to the kFSEventStreamEventFlagMustScanSubDirs flag to indicate that a problem occurred in buffering the events (the particular flag set indicates where the problem occurred) and that the client must do a full scan of any directories (and their subdirectories, recursively) being monitored by this stream. If you asked to monitor multiple paths with this stream then you will be notified about all of them. Your code need only check for the kFSEventStreamEventFlagMustScanSubDirs flag; these flags (if present) only provide information to help you diagnose the problem.

p.s.
I am tried MacFSEvents because it do not work well with my Mac.
MacFSEvents

[BoboTiG]

Isn't it good since #717?