[devtools] Make timeout error in qunit tests configurable and use SkipTest in test_jscript.py
This is grafted from 87443f279b0f in default branch (got tired of CI failing
because of these unreliable tests).
from cubicweb.cwconfig import CubicWebConfiguration
def includeme(config):
appid = config.registry.settings['cubicweb.instance']
cwconfig = CubicWebConfiguration.config_for(appid)
config.registry['cubicweb.config'] = cwconfig
config.registry['cubicweb.repository'] = repo = cwconfig.repository()
config.registry['cubicweb.registry'] = repo.vreg