see this new page. That allows me to inflict pain on testbed
developers while we work out any kinks. These new pages implement an
XML interface to experiment creation.

Some new files:

beginexp_html.php3: A wrapper for the actual beginexp form. This page
includes the form, and then invokes the XMLRPC backend page.

beginexp_form.html: The original form code, split out from beginexp
and turned into a module that can be included into another file.  It
is slightly reorganized to make it easier to include as a module.  The
idea is that the plab_ez form will be recast in this model, reducing
some redundant complexity.

beginexp_xml.php3: The XML backend. The idea is that the html page
packages up the form arguments as an XMLRPC message, and invokes this
page with the XML goo encoded in the URL. It also passes along the
uid/cookie so that the authentication happens properly (https of
course). The page decodes the URL into PHP datatypes, and ...