[testlib] consider rset for template / view selection (closes #2447183)
The original code did something like:
kwargs['rset'] = rset
viewfunc = lambda **k: viewsreg.main_template(req, template, **kwargs)
kwargs.pop('rset')
return self._test_view(viewfunc, view, template, kwargs)
meaning that by the time ``viewfunc`` (i.e. the lambda function) is called,
``rset`` was popped from ``kwargs`` and had no chance to be passed to ``main_template``.
<table class="attributeForm" style="width:100%;"
tal:attributes="id tab_id | nothing;
class tab_class | nothing;">
<tr tal:iter="widget lines">
<th class="labelCol" tal:content="structure python:widget.render_label(entity)">attrname</th>
<td tal:define="error python:widget.render_error(entity)" style="width:100%;"
tal:attributes="class python:error and 'error' or nothing">
<div tal:replace="structure error">error message if any</div>
<div tal:replace="structure python:widget.edit_render(entity)" >widget (input, textarea, etc.)</div>
<div tal:replace="structure python:widget.render_help(entity)">format help if any</div>
</td>
</tr>
</table>