Use internal AGS for print task server

This print server won't be available to users who clone the repo
which will be an incentive to provide their own server settings.
It also enables us to use custom print templates which we've created
locacally.
Add mxd printing templates with custom layout

These are modified versions of the default "Letter ANSI A Landscape"
and "Letter ANSI A Portrait" mxds that ship with AGS, providing more
room for a multicolumn legend, a logo and optimized map spacing.
Files with "Legend" in their name, occupy the legend space with the
map.
Remove PageSize and fixup UI markup

PageSize is no longer a parameter for printing, we assume Letter ANSI A
size.  This was to support custom printing, which requires new templates
to be created, so we dropped support for the less used sized.

Also cleaned up the markup so it wouldn't rely so heavily on floats and
paddings to achieve the layout, and closed input tags correctly
Add optional print template prefix to settings

If left blank, the framework will try to load the default AGS print
template
but if set, uses the value to construct the template name to use.
Allow for custom templates in export