Fix injection of psycopg2 schema_path options

I was injecting multiple times the schema_path option, as I was assuming
that that part of the codepath would not be reentered after startup.
I was wrong, and this was causing the SSL handshake to mess up.
Modify "delete test database" confirmation to flush on subprocess pass-thru

When using django's testing framework with subprocess,
the prompt to confirm that the testing database was not printing
properly due to buffering. This explicitly flushes the buffer, which
is required for something interactive like this.