pjproject: Fix for Solaris builds. Do not undef s_addr.

pjproject: Fix for Solaris builds. Do not undef s_addr.

pjproject, in order to solve build problems on Windows [1], undefines s_addr in
one of it's headers that is included in res_rtp_asterisk.c. On Solaris s_addr
is not a structure member, but defined to map to the real strucuture member,
therefore when building on Solaris it's possible to get build errors like:

    [CC] res_rtp_asterisk.c -> res_rtp_asterisk.o
    In file included from /export/home/admin/asterisk-11-svn/include/asterisk/stun.h:29,
                     from res_rtp_asterisk.c:51:
    /export/home/admin/asterisk-11-svn/include/asterisk/network.h: In function `inaddrcmp':
    /export/home/admin/asterisk-11-svn/include/asterisk/network.h:92: error: structure has no member named `s_addr'
    /export/home/admin/asterisk-11-svn/include/asterisk/network.h:92: error: structure has no member named `s_addr'
    res_rtp_asterisk.c: In function `ast_rtp_on_ice_tx_pkt':
    res_rtp_asterisk.c:706: warning: dereferencing type-punned pointer will break strict-aliasing rules
    res_rtp_asterisk.c:710: warning: dereferencing type-punned pointer will break strict-aliasing rules
    res_rtp_asterisk.c: In function `rtp_add_candidates_to_ice':
    res_rtp_asterisk.c:1085: error: structure has no member named `s_addr'
    make[2]: *** [res_rtp_asterisk.o] Error 1
    make[1]: *** [res] Error 2
    make[1]: Leaving directory `/export/home/admin/asterisk-11-svn'
    gmake: *** [_cleantest_all] Error 2

Unfortunately, in order to make this work, I also had to make sure pjproject
only used the typdef pj_in_addr and not the struct pj_in_addr so that when
building Asterisk I could "typedef struct in_addr pj_in_addr". It's possible
then that the library and users of those interfaces in Asterisk have a different
idea about the type of the argument, while on the surface it looks like they are
all 32 bit big endian values.

[1] http://trac.pjsip.org/repos/changeset/484

(issues ASTERISK-20366)
Reported by: Ben Klang
Tested by: Ben Klang, mjordan
patches:
  0001-pjproject-Fix-for-Solaris-builds.-Do-not-undef-s.patch uploaded by Shaun Ruffell (license 5417)
........

Merged revisions 374642 from http://svn.asterisk.org/svn/asterisk/branches/11

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@374643 65c4cc65-6c06-0410-ace0-fbb531ad65f3