Summary: Implement basic kqueue/kevent backend for eio. When it comes to tracking directory changes, this backend falls back to the polling one.
Test Plan: Ran Enlightenment for several days and some other EFL apps without any issue.
Reviewers: cedric
Reviewed By: cedric
Subscribers: cedric
Projects: #e_on_freebsd, #efl
Differential Revision: https://phab.enlightenment.org/D2983
Signed-off-by: Cedric BAIL <cedric@osg.samsung.com>