By specifying <vendor> element in CPU requirements a guest can be
restricted to run only on CPUs by a given vendor. Host CPU vendor is
also specified in capabilities XML.
The vendor is checked when migrating a guest but it's not forced, i.e.,
guests configured without <vendor> element can be freely migrated.
The virConnectPtr is no longer required for error reporting since
that is recorded in a thread local. Remove use of virConnectPtr
from all APIs in cpu_conf.{h,c} and update all callers to
match
* include/libvirt/virterror.h src/util/virterror.c: add new domain
VIR_FROM_CPU for errors
* src/conf/cpu_conf.c src/conf/cpu_conf.h: new parsing module
* src/Makefile.am proxy/Makefile.am: include new files
* src/conf/capabilities.[ch] src/conf/domain_conf.[ch]: reference
new code
* src/libvirt_private.syms: private export of new entry points