[SyncEvolution] Concurrent sync sessions update - Almost done

Hi Patrick, We've now got the GIO GDBus issues fixed and all the non-autosync & non-connection tests pass with both DBus wrappers. We are currently going through the code and making sure code is commented properly, debugging output is cleaned up and header files are organized more cleanly. The uncleaned code is in the knowak/for-Chris branch. We don't suspect to be making anymore logic changes to that, just clean it up. The clean-up will be finished tomorrow and I'll place it in a branch named concurrent-sync-sessions-for-review. Cheers, Chris