As it was basically unimplemented and more confusing than useful
at the moment.
* src/libvirt_private.syms: remove from internal symbols list
* src/qemu/qemu_bridge_filter.c src/util/ebtables.c: remove code and
one use of the unimplemented function
* src/internal.h (ATTRIBUTE_SENTINEL): New, it's a ggc feature and
protected as such
* src/util/buf.c (virBufferStrcat): Use it.
* src/util/ebtables.c (ebtablesAddRemoveRule): Use it.
* src/util/iptables.c (iptableAddRemoveRule: Use it.
* src/util/qparams.h (new_qparam_set, append_qparams): Use it.
* docs/apibuild.py: avoid breaking the API generator with that new
internal keyword macro
* configure.in: look for ebtables binary location if present
* src/Makefile.am: add the new module
* src/util/ebtables.[ch]: new module and internal APIs around
the ebtables binary
* src/libvirt_private.syms: export the symbols only internally
