Add test utility functions to wait for device, some test fixes

These are used in a few different places, and may be useful to others writing integration tests.

Default sleep time between retries reduced from 30 ms to 20 ms to allow slightly faster tests.

The databaseds tests now wait for the server to start up by checking the output instead of just sleeping 1 second. This is more reliable.

Similarly, test_restart_simple_server, will wait much longer for the new server to come up.

Enabled logging during test runs to help diagnose failed tests.