efl: common inotify checks, simplified.

efl: common inotify checks, simplified.

Another try to make inotify checks more common.

This time uses AC_CHECK_HEADERS() as for others, that already define
HAVE_SYS_INOTIFY_H, then uses that.

I still kept AM_CONDITIONAL([HAVE_INOTIFY]) because I plan to convert
ecore_file to the same, smarter, method that is used in eio (compiling
the file depending on the backend.

SVN revision: 80358