[devtools] qunit: update to 1.18.0 (closes #5533333) * the logging API has changed (register callbacks instead of setting attributes on the QUnit object) * the logging callbacks all have a single "details" object argument * the "main" div was renamed to "qunit-fixture" (this change is responsible for all the churn in our own JS test files) * QUnit can now build the DOM elements it needs for reporting from a single "qunit" div

import ConfigParser
try:
    undo_actions = config.cfgfile_parser.get('MAIN', 'undo-support', False)
except ConfigParser.NoOptionError:
    pass # this conf. file was probably already migrated
else:
    config.global_set_option('undo-enabled', bool(undo_actions))