Merge remote-tracking branch 'upstream/master' into oracle_trigger2

this is an improved version of the oracle "auto_increment" trigger. If there is an id in the data supplied it takes this value, and if this value is lower than the current sequence value, the sequence is changed to be incremented by the difference the next time it is used.

This works around the problem of the sequence producing ids already in the database.

The disadvantage of this version is, that the sequence is modified at every run of the trigger.