[LMS-2260]

added: creation of screening database
added: 'admin' and 'etlserver' users are precreated. The installer wizzard generates a passoword for 'etlserver'
added: allow the user to specify a path for the location of 'psql' and 'pg_dump'
fixed: the normal installation process was broken, because the 'service.properties' within the distributables contained installer placeholders. Now the installer merges its properties on the top of the old-style properties
update: the installer wizzard no longer pretends it can support arbitrary PostgreSQL installations. It simply informs the user it requires a "trust" setting to be configured for the local users.

SVN: 21393