postgresql driver: escape backslashes only when server requires it

Task-number: QTBUG-30076

Change-Id: I408cda941884f01484d0edfa82c91fc19cb8718c
Reviewed-by: Israel Lins Albuquerque <israelins85@yahoo.com.br>
Reviewed-by: Sergey Blagodarin
Reviewed-by: Andy Shaw <andy.shaw@digia.com>
Reviewed-by: Andras Mantia <andras@kdab.com>
(cherry picked from qtbase/e3c5351d06ce8a12f035cd0627356bc64d8c334a)
Reviewed-by: Mark Brand <mabrand@mabrand.nl>
Tools: unnecessary to make qmlplugindump a bundle

Embed Info.plist in qmlplugindump executable in a special way.

Change-Id: Ia83cf15a1dc8c7e37560a280bd711ff2e4468ad8
(adpated from qtdeclarative/4d173d5f16c103f640d4089feed44a74b14e9004)
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>