Skip tests for ldapsource with python >= 3.7 Until someone works on fixing these, this should make our CI green again. I tried to use setupModule() to check for python version, but pre_setup_database() is apparently called even when a SkipTest exception is raised there. So handle this in that method.

[doc] Update cubicweb-ctl page about how to run an instance * remove mention of start/stop/restart/status commands that do not exist anymore * briefly mention the "pyramid" and point to respective documentation page * mention that a WSGI server should be used in production

[doc] Drop mention of the "pyramid" cube This cube got merged into cubicweb several versions ago.