UTIL: Add a generic inotify module Adds a reusable module for watching files using the Linux-specific inotify(7) interface. Adds the possibility to watch the file's parent directory as well to make it possible to watch moves into the directory and allow watching file that doesn't exist at the time the watch is created. This interface is needed to implement the files provider, so this commit is related to: https://fedorahosted.org/sssd/ticket/2228 Reviewed-by: Pavel Březina <pbrezina@redhat.com>

BUILD: Fix a typo in inotify.m4 This typo prevented HAVE_INOTIFY from ever being set and as an effect, prevented /etc/resolv.conf inotify detection from working Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com> Reviewed-by: Fabiano Fidêncio <fidencio@redhat.com>

AUTOTOOLS: More robust detection of inotify. We checked only header file "sys/inotify" for detection whether inotify works. Some platforms do not have built in inotify, but contain library, which provides inotify-compatible interface. This patch adds more robust detection of inotify in configuration time and appends linker flags to Makefile if inotify is provided by library.