Berkeley DB version

[Henrique de Moraes Holschuh]

Please lock to the Berkeley DB version used by OpenLDAP.  If they're still
at 4.7, so should we be.  If they are going to 4.8, we can consider that.

-- 
  "One disk to rule them all, One disk to find them. One disk to bring
  them all and in the darkness grind them. In the Land of Redmond
  where the shadows lie." -- The Silicon Valley Tarot
  Henrique Holschuh