Use Popen to start virtual keyboard

Before, the virtual keyboard was started by appending `&` and using
`check_call` with the `shell=True` argument. A cleaner and more secure
method is to use Popen directly.
Stop calling `nmcli` when it is not installed
Remove commented out lines
Wrap lines to 80 chars
Remove unnecessary commas
Check if old config files exist before migration
Fix typo in `interpret_shell_line` options
Clarify license keyword argument in setup.py
Log an error and exit if rotation direction is bad
Merge remote-tracking branch 'jturner314/log-bad-direction' into python3
Merge remote-tracking branch 'jturner314/fix-config-migration' into python3
Merge remote-tracking branch 'jturner314/fix-network-restart' into python3
Merge remote-tracking branch 'jturner314/clarify-license-metadata' into python3
Merge remote-tracking branch 'jturner314/use-popen' into python3