libnet: fix i486 sample synflood6 warning

synflood6.c: In function 'main':
synflood6.c:157: warning: format '%ld' expects type 'long int', but argument 2 has type 'unsigned int'

Signed-off-by: Gilles Espinasse <g.esp@free.fr>
libnet: use LIBNET_*RESOLVE const in libnet_name2addr*

and fix tab vs space issue in that changed line

Signed-off-by: Gilles Espinasse <g.esp@free.fr>
libnet: libnet_build_snmp fix warning

Usign -Wstrict-prototypes show:
libnet_build_snmp.c:36:1: warning: function declaration isn't a prototype [-Wstrict-prototypes]

Signed-off-by: Gilles Espinasse <g.esp@free.fr>
Prepare for 1.2 release candidate 2
Notes on how to build from a git checkout.