[libvirt] [for 1.2.6] Redundancy of virNetworkGetDHCPLeases and virNetworkGetDHCPLeasesForMAC

Hi, when reviewing the patch to add python bindings for the said APIs it occurred to me that the two APIs are so close in their prototypes and way of functioning that we could actually merge them into one. Both of those return a list of lease structures and the only difference is the presence of the @mac argument. We could unify those two APIs into one with the following signature: int virNetworkGetDHCPLeases(virNetworkPtr network, const char *mac, virNetworkDHCPLeasePtr **leases, unsigned int flags) And tweak the semantics of @mac where when the user passes NULL we'd return the complete unfiltered list. This would simplify our API and also the python bindings. If we decide this is a good idea (in time for the release) I'll post patches to flesh out the redundant parts. Peter