New Design Center API

Integrates new Design Center API, which implements vastly improved Design Center operations, including:

- Installation, configuration and activation of sketches
- Definition of run environments and named parameter sets, for more powerful configuration.
- Definition of compositions, which allow automatically transferring results between sketches.
- Big performance improvements in every operation.
- Many other improvements.

The cf-sketch tool has been updated to use the new API, some commands still remain to be ported.