core:  exportDbSchema scripts generates output...

exportDbSchema scripts generates output file with wrong name

1) Fixing the file name by using psql directly
2) Fixing -v to display more info
3) Adding a missing PORT parameter

Change-Id: I3d05e96f4abc66e293db23af89285b0653025537
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=1009899
Signed-off-by: Eli Mesika <emesika@redhat.com>