Make get_xmlrpc_config a bit more verbose in case of C++ errors
At the moment, the checks performed by get_xmlrpc_config at configuration time, to detect xmlrpc-c C++ build options, will only report whether builds are succesfull or not, and so which recipe worked.
This isn't easy to debug, in case of failures, when building happens inside a chrooted environment or similar (typically with pbuilder/cowbuilder for Debian packages generation).
I think it could be interesting to display the logs instead of silently discarding them.
See the proposed patch in debian/patches/verbosesconsrecipe.diff committed in http://anonscm.debian.org/cgit/pkg-opennebula/opennebula.git/diff/debian/patches/verbosesconsrecipe.diff?id=8f7a457c6116621be51f11d0f66c454212400bd3
Thanks in advance.