Use inet_pton instead; pull in gnulib's module by the same name.
* src/network_conf.c (virNetworkDefParseXML): Use inet_pton,
rather than inet_aton.
* bootstrap (modules): Add inet_pton.
* gnulib/lib/inet_pton.c: New file, from gnulib.
* src/domain_conf.c, src/network_conf.c, src/storage_conf.c:
Improve error messages from commands such as 'virsh define'
when the XML is not well-formed by passing libxml2 errors
back out through virterror.
