RPC: Don't accept client if it would overcommit max_clients
RPC: Don't accept client if it would overcommit max_clients

Currently, even if max_client limit is hit, we accept() incoming
connection request, but close it immediately. This has disadvantage of
not using listen() queue. We should accept() only those clients we
know we can serve and let all other wait in the (limited) queue.

VenkatDatta/libvirt,cbosdo/libvirt,eskultety/libvirt,datto/libvirt,eskultety/libvirt,fabianfreyer/libvirt,jfehlig/libvirt,shugaoye/libvirt,zippy2/libvirt,jfehlig/libvirt,VenkatDatta/libvirt,cbosdo/libvirt,jardasgit/libvirt,elmarco/libvirt,fabianfreyer/libvirt,cbosdo/libvirt,olafhering/libvirt,libvirt/libvirt,jfehlig/libvirt,zhlcindy/libvirt-1.1.4-maintain,fabianfreyer/libvirt,taget/libvirt,rlaager/libvirt,zhlcindy/libvirt-1.1.4-maintain,agx/libvirt,datto/libvirt,datto/libvirt,datto/libvirt,elmarco/libvirt,eskultety/libvirt,andreabolognani/libvirt,olafhering/libvirt,taget/libvirt,shugaoye/libvirt,agx/libvirt,zippy2/libvirt,shugaoye/libvirt,zhlcindy/libvirt-1.1.4-maintain,VenkatDatta/libvirt,jfehlig/libvirt,nertpinx/libvirt,zhlcindy/libvirt-1.1.4-maintain,VenkatDatta/libvirt,rlaager/libvirt,taget/libvirt,taget/libvirt,shugaoye/libvirt,elmarco/libvirt,VenkatDatta/libvirt,libvirt/libvirt,olafhering/libvirt,rlaager/libvirt,datto/libvirt,rlaager/libvirt,andreabolognani/libvirt,cbosdo/libvirt,eskultety/libvirt,andreabolognani/libvirt,jardasgit/libvirt,jardasgit/libvirt,andreabolognani/libvirt,agx/libvirt,elmarco/libvirt,nertpinx/libvirt,rlaager/libvirt,zhlcindy/libvirt-1.1.4-maintain,jardasgit/libvirt,taget/libvirt,crobinso/libvirt,crobinso/libvirt,eskultety/libvirt,nertpinx/libvirt,nertpinx/libvirt,agx/libvirt,cbosdo/libvirt,crobinso/libvirt,fabianfreyer/libvirt,zippy2/libvirt,jardasgit/libvirt,olafhering/libvirt,nertpinx/libvirt,libvirt/libvirt,elmarco/libvirt,agx/libvirt,zippy2/libvirt,libvirt/libvirt,andreabolognani/libvirt,fabianfreyer/libvirt,crobinso/libvirt,shugaoye/libvirt