[fsnotify] report #7

[Ilya Putsikau]

Done this week:
* Add write, close and inactive hooks
* Don't send write, close and inactive events for directories
* Clear node changed flag in inactive hook
* Get cookie number only when needed
* Change hooking mechanism to store function pointers in structure
* Use macros to lock/unlock mutexes
* Fix node_lookupex bug

Milestones planned for the first part of Summer Of Code are complete now.