Support dialog configuration via YAML

[BlueM]

Pashua’s current dialog configuration is ugly, redundant and verbose, and as it is a proprietary format, there is no 3rd party code which could be used for parsing it.

It seems to me that using YAML instead would be a much better fit. As this would be a BC break, a feasible approach (on the Pashua side) could be: try to parse the dialog configuration as YAML, then use the Pashua legacy format. This ways, Pashua users could choose when to migrate their scripts.

[cylott]

What a great idea. I'd love to be able to parse a YAML file and hand that off to Pashua.