Unbreak editors/openoffice-* build when GCONF and GNOMEVFS are disabled

There is a missing dependency on devel/dbus-glib that causes the
openoffice build to fail when the GCONF and GNOMEVFS options are
disabled. When these options are enabled, one of the dependencies
added by these options brings along dbus-glib so the default build
succeeds.

There is a configure knob to control whether or not dbus-glib is
used, so follow the lead of the libreoffice port and rename the
GCONF option to GNOME and bundle both Gconf and DBUS handling under
the GNOME option.

Borrow the MMEDIA option from the libreoffice port and use that to
control the using of gstreamer.

Add a couple of missing p5-* build dependencies.

Add the --enable-gtk, --disable-kde, --disable-kde4 configure flags
so that the port does not try to build with KDE if it is installed
because compilation fails.

USE_AUTOTOOLS=autoconf -> USES=autoreconf:autoconf

PR: 199865
Reported by: pi
Differential Revision: https://reviews.freebsd.org/D2441
Reviewed by: pi, pfg
Approved by: mat (mentor)