All tests which could avoid calling scan() directly have been
changed to use the 'full_scan' argument to get_ordered_network.
This was done because of unreliable scanning behavior on slower
systems, like VMs. If we get unlucky with the scheduler some beacons
are not received in time and in turn scan results are missing.
Using full_scan=True works around this issue by repeatedly scanning
until the SSID is found.
With the addition of connect_bssid/roam very few tests actually
require hwsim. Since hwsim can lead to problems with scan results
its best to have it off by default and have each test that needs
it explicitly turn it on.
Tests which previously turned it off have had that option removed.
Tests that do require hwsim still are vulnerable to scan result
problems, so for these tests beacon_int was added to the hostapd
config which seems to help with reliability somewhat.
