'const fooPtr' is the same as 'foo * const' (the pointer won't
change, but it's contents can).  But in general, if an interface
is trying to be const-correct, it should be using 'const foo *'
(the pointer is to data that can't be changed).

Fix up offenders in src/util outside of the virnet namespace.

Also, make a few virSocketAddr functions const-correct, for easier
conversions in future patches.

* src/util/virbuffer.h (virBufferError, virBufferUse)
(virBufferGetIndent): Use intended type.
* src/util/virmacaddr.h (virMacAddrCmp, virMacAddrCmpRaw)
(virMacAddrSet, virMcAddrFormat, virMacAddrIsUnicast)
(virMacAddrIsMulticast): Likewise.
* src/util/virebtables.h (ebtablesAddForwardAllowIn)
(ebtablesRemoveForwardAllowIn): Likewise.
* src/util/virsocketaddr.h (virSocketAddrSetIPv4Addr): Drop
incorrect const.
(virMacAddrGetRaw, virSocketAddrFormat, virSocketAddrFormatFull):
Make const-correct.
(virSocketAddrMask, virSocketAddrMaskByPrefix)
(virSocketAddrBroadcast, virSocketAddrBroadcastByPrefix)
(virSocketAddrGetNumNetmaskBits, virSocketAddrGetIpPrefix)
(virSocketAddrEqual, virSocketAddrIsPrivate)
(virSocketAddrIsWildcard): Use intended type.
* src/util/virbuffer.c (virBufferError, virBufferUse)
(virBufferGetIndent): Fix fallout.
* src/util/virmacaddr.c (virMacAddrCmp, virMacAddrCmpRaw)
(virMacAddrSet, virMcAddrFormat, virMacAddrIsUnicast)
(virMacAddrIsMulticast): Likewise.
* src/util/virebtables.c (ebtablesAddForwardAllowIn)
(ebtablesRemoveForwardAllowIn): Likewise.
* src/util/virsocketaddr.c (virSocketAddrMask, virMacAddrGetRaw)
(virSocketAddrMaskByPrefix, virSocketAddrBroadcast)
(virSocketAddrBroadcastByPrefix, virSocketAddrGetNumNetmaskBits)
(virSocketAddrGetIpPrefix, virSocketAddrEqual)
(virSocketAddrIsPrivate, virSocketAddrIsWildcard)
(virSocketAddrGetIPv4Addr, virSocketAddrGetIPv6Addr)
(virSocketAddrFormat, virSocketAddrFormatFull): Likewise.
Signed-off-by: NEric Blake <eblake@redhat.com>

https://www.gnu.org/licenses/gpl-howto.html recommends that
the 'If not, see <url>.' phrase be a separate sentence.

* tests/securityselinuxhelper.c: Remove doubled line.
* tests/securityselinuxtest.c: Likewise.
* globally: s/;  If/.  If/

Per the FSF address could be changed from time to time, and GNU
recommends the following now: (http://www.gnu.org/licenses/gpl-howto.html)

  You should have received a copy of the GNU General Public License
  along with Foobar.  If not, see <http://www.gnu.org/licenses/>.

This patch removes the explicit FSF address, and uses above instead
(of course, with inserting 'Lesser' before 'General').

Except a bunch of files for security driver, all others are changed
automatically, the copyright for securify files are not complete,
that's why to do it manually:

  src/security/security_selinux.h
  src/security/security_driver.h
  src/security/security_selinux.c
  src/security/security_apparmor.h
  src/security/security_apparmor.c
  src/security/security_driver.c

Introduce new members in the virMacAddr 'class'
- virMacAddrSet: set virMacAddr from a virMacAddr
- virMacAddrSetRaw: setting virMacAddr from raw 6 byte MAC address buffer
- virMacAddrGetRaw: writing virMacAddr into raw 6 byte MAC address buffer
- virMacAddrCmp: comparing two virMacAddr
- virMacAddrCmpRaw: comparing a virMacAddr with a raw 6 byte MAC address buffer

then replace raw MAC addresses by replacing

- 'unsigned char *' with virMacAddrPtr
- 'unsigned char ... [VIR_MAC_BUFLEN]' with virMacAddr

and introduce usage of above functions where necessary.

* global: patch created by running:
for f in $(git ls-files '*.[ch]') ; do
    cppi $f > $f.t && mv $f.t $f
done

* 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