Allow aliased field names with separated syntax

Allow aliased field names with separated syntax

This introduce the syntax from aliased table names for aliased field
names into the abstract database layer:

array( 'alias' => 'field' ) gives 'field AS alias'

This patch also includes changes to query pages, api and some more
places to show, how the new syntax looks in "production".

This allow us to remove the "AS" for Non-PostgreSQL databases, if we
want that.

Change-Id: I5f0de1c2f29092c173aec3de93ffdef436799e8d