testXHTML: test portal types also from tools

Some portal types such as Business Template were not tested by testXHTML
because this tests started by modules and recursively tests views based
on allowed content types. Because of this approach, types that are not
created in a module but in a tool were never tested.

With unittest, the only way to dynamically add test methods to a class
is to generate a test class in test_suite function. At this stage, the
ERP5 site is not created yet, so the test had to introspects business
templates XML.

This now uses a slightly different approach, instead of finding modules
and chain of allowed content types from business template XML, we only
use business template to introspect the list of actions.
The lookup of the appropriate containers is no longer done before setup
by static analysis of business templates XML, but later once the site is
created, by dynamic analysis of the modules and allowed content types on
the running ERP5 site during the test method.
If we don't find a chain of portal types, we create the test document in
portal_trash, a tool without filter of content types.

This way, we can test all views of all portal types. This revealed a few
problems:
 - we need developer role to create components in portal_components, for
this we add developer role to the current user.
 - Delivery Cell portal type looks not used, there are no container
accepting it. We don't test delivery cell views for this reason.
 - VCS view on business template needs preferences and working copy
setup. We just mark this test as expected failure for now.
 - Solver Decision has a form conditionnaly displayed when there's a
relation to a solver, but this test does not evaluate action conditions
and does not allow to call a script (that would made it possible to
modify the document so that the condition is true). For now we also
mark this as expected failure.