- Add to qvm-run:
- no-gui when command doesn't require a GUI
- filter-escape-chars when pass-io is set and output is not a file,
such as a pipe that could later be used to print information.
- Change remaining echo to printf
- Add end-of-options separator when possible
Echo can interpret operand as an option and checking every variable to
be echoed is troublesome while with printf, if the format specifier is
present before the operand, printing as string can be enforced.
