Solaris builds of libssh2-1.2.3 failed on both x64 and UltraSPARC
platforms because of two problems:
1) src/agent.c:145 sun is a reserved word when using the SUNWspro compiler
2) example/direct_tcpip.c:84 INADDR_NONE is not defined
buildconf copies the template to example/ and configure makes sure
to generate a proper file from it and the direct_tcpip.c example
is the first one to use it - to make sure it builds fine on more
paltforms