Log Message:
Changes 3.2.3:
* Provide compilation option for GTK+3 as well as GTK+2
* Make program configuration check for _POSIX_CLOCK_SELECTION as
  well as _POSIX_MONOTONIC_CLOCK when checking the availability of
  monotonic clocks for condition variables (corrects BSD builds)
* Ensure PIPE_BUF is defined in mainwindow.cpp (corrects Hurd build).
* Upgrade internal c++-gtk-utils version to 1.2.3.

Changes 3.2.2:
* Update internal copy of c++-gtk-utils to version 1.2.2 and fix
  compilation error with gcc-4.5.0.
* Provide an automatic redial option where the modem is in use or
  the recipient of a fax is busy.
* Get GUI to deal with a corner case where sending a fax from the
  socket server to an empty number (open connection) is cancelled.
* Provide an error dialog if, on program start-up, a connection to
  the dbus session message bus cannot be established.
* Use Cgu::start_timeout_seconds() instead of Cgu::start_timeout()
  where glib supports it, and so bump c++-gtk-utils requirement to
  version 1.2.1.