More precise inotify related function signatures

[thg2k]

Changes

1. inotify_add_watch: Narrowed the returned value: It can only be a non-negative integer according to the man page
2. inotify_add_watch: Added false in case of failure, same concept as fopen(), in case the file does not exist or is not readable
3. inotify_queue_len: Narrowed the return value: It can only be zero or positive
4. inotify_read: Narrowed the return value: Added the shape of the returned array
5. inotify_read: Added false in case the stream is set a non-blocking.

Question: I have a doubt about point 5, i.e. adding false as possible return type to inotify_read. This can only happen if the inotify stream is set as non-blocking (tested). Should this go to the bleeding version of the signatures map?

[ondrejmirtes]

Let's try this like that :) Thank you!