Fixes possible api misuse when connecting with server

[Ranier Vilela]

Hi.

IMO, I think that some sources can have api misuse.

The functions * PQconnectdbParams* and * PQconnectdb*,
can return NULL and need a handler too.
More, if a connection fail with CONNECTION_BAD, some
sources do not handle correctly when failing.
Must call PQfinish, to release OS resources.

Patches attached.

best regards,
Ranier Vilela

fix-connection-api-miuse-connect_utils.patch
Description: Binary data

fix-connection-api-miuse-ecpg.patch
Description: Binary data

fix-connection-api-miuse-pg_rewind.patch
Description: Binary data

fix-connection-api-miuse-psql.patch
Description: Binary data

fix-connection-api-miuse-pg_createsubscriber.patch
Description: Binary data