Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

In many places we define a variable as a 'const char *' when in fact
we modify it just a few lines below. Or even free it. We should not do
that.

There's one exception though, in xenSessionFree() xenapi_utils.c. We
are freeing the xen_session structure which is defined in
xen/api/xen_common.h public header. The structure contains session_id
which is type of 'const char *' when in fact it should have been just
'char *'. So I'm leaving this unmodified, just noticing the fact in
comment.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

https://bugs.gentoo.org/show_bug.cgi?id=508336

At wireshark, they have this promise to change public dissector APIs
only with minor version number change. Which they did when releasing
the version of 1.12.

Firstly, they've changed tvb_memdup() in
a0c53ffaa1bb46d8c9db2ec739401aa411c9790e so now it takes four arguments
instead of three. The new argument is placed at the very beginning of
the list of arguments and basically says the scope where we'd like to
allocate the memory. According to the documentation NULL should be the
default value.

Then, the tcp_dissect_pdus() signature changed too. Well, the function
that actually dissects reassembled packets as tcp_dissect_pdus()
reorder TCP packets into one big chunk and then calls a user function
to dissect the PDU at once. The change is dated back to
8081cf1d90397cbbb4404f9720595e1537ed5e14.

Then, WS_DLL_PUBLIC_NOEXTERN was replaced with WS_DLL_PUBLIC_DEF in
5d87a8c46171f572568db5a47c093423482e342f.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

The rationale is to not duplicate code which is done in
packet-libvirt.h for instance. Moreover, this way we can drop
__attribute_((unused)) used int packet-libvirt.c in favor of
ATTRIBUTE_UNUSED.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Introduce Wireshark dissector plugin which adds support to Wireshark
for dissecting libvirt RPC protocol.
Added following files to build Wireshark dissector from libvirt source
tree.
* tools/wireshark/*: Source tree of Wireshark dissector plugin.

Added followings to configure.ac or Makefile.am.
configure.ac
* --with-wireshark-dissector: Enable support for building Wireshark
  dissector.
* --with-ws-plugindir: Specify wireshark plugin directory that dissector
  will installed.
* Added tools/wireshark/{Makefile,src/Makefile} to  AC_CONFIG_FILES.
Makefile.am
* Added tools/wireshark/ to SUBDIR.