databases/cego: update 2.38.20 -> 2.39.1

• Introduced table locking statements to set an explicit lock on a table ( e.g. for update synchronisation ). This feature replaces the "set update sync on/off" command
• Trigger implementation basically completed
• Fix in CegoQueryHelper::encodeFVL, for blob/clob values lists, the corresponding index variables ( blobidx/clobidx ) have not been increaed while encoding lob data. This might lead to invalid results and seg faults in case of multiple lobs values in one insert/update operation.

Submitted by: Bjoern Lemke <lemke@lemke-it.com>