Altium 19 stack manager and Gerber file setup
Altium 19 has moved things around.

With the Stackup manager window being active, if you click File, you will see "Save Template as" and "Load Template". This is the equivalent of what you are looking for.

As for the board outline, I use a mechanical layer for the board outline and export it along with the rest of the gerber files and in a document state what the different layers are, including the mechanical layer being the board outline.