This introduces new syntax which allows to set multiple options at once,
as to align with atomic modesetting semantics.

It's pretty simple:

- kscreen-doctor receives a list of "commands"
- each command translates to one setting of an output
- in general, the output commands are separated by '.'

Commands can be (currently limited to, but it gets you the idea):

// Disable an output
kscreen-doctor output.1.disable

// Enable an output, set a specific mode
kscreen-doctor output.1.enable output.1.mode.3

// Position outputs next to each other
kscreen-doctor output.1.position.0,0 output.2.position.1920,0

You can use the --outputs option to find the ids for outputs and modes.