Remove a useless “givin up” debug line

Add a missing "virtual", and remove a trivial "private" redundancy

Re-connect to postgresql when the connection is lost

fix #3336

Actually display the error message from postgresql when a query failed

Remove all the ugly database debug

Merge branch 'postgresql' into 'master'

Add postgresql support

Closes #3237

See merge request louiz/biboumi!18

Always free the PGresult pointer returned by PQexec

Fix a somewhat big memory leak

Fix a few warnings

Add postgresql support