Fix checks not running as expected after suspend

g_timeout-s use monotonic time, which doesn't get counted when the system is
suspended. As a result, the next automatic checks or the paused period would not
run when expected after a suspend.

We now use our own timeouts (via timerfd) using real time for next auto checks
and paused period.
Refactor escaping for notifications (Fix #3)

We now escape a few more characters, thus fixing a bug where notification-daemon
would not show the summary text if a '<' was used.
Escaping is only done on the fields where it applies (i.e. not for sizes, etc)
when send to notification (i.e. not for tty output), thus assuming that
user-provided templates are correctly escaped (to allow the use of tags, for
bold, etc).
Code adjustments for pacman-4.1 API changes
kalu-dbus: Use new caller prefix with alpm_logaction()
kalu-dbus: optional dependencies are now alpm_depend_t* instead of char*
Add support for new event ALPM_EVENT_OPTDEP_REQUIRED
kalu-dbus: Add note about why we ignore ALPM_EVENT_DATABASE_MISSING
Add progress for "checking keyring"
Add message for EVENT_KEY_DOWNLOAD
Fix event retrieving-pkgs: only one, instead of one per repo
Add support of events for downgrade & reinstall
Parse UseDelta value in locale-independent way

strtod() is locale dependent, but reading the config should always be done
regardless of user's locale. (See FS#34253)
Watched (AUR) window: Put list inside a scrolled window
Fix setlocale() only called when NLS enabled
Add menu "Show unread news" to help marking them read

Not so much to avoid running all checks (just re-show notifs) but for people who
do not have buttons shown on notifications.
kalu-dbus: Remove call to deprecated function
Bump to 2.0.0; Update HISTORY