KolabMailSynchronizer: stability fixes, speedup
KolabMailSynchronizer: stability fixes, speedup

* unset SideCache cache location bit in InfoDb if object
  is not found in SideCache (InfoDb/SideCache consistency
  error situation)
* in transaction_prepare(), avoid double conversion of
  Kolab_conv_mail (clone-and-throw-away instead)
* in info_sync(), put all InfoDb accesses into one
  transaction

GNOME/evolution-kolab,GNOME/evolution-kolab