In the SDL version.

Adds this CPU speed print support to the web debug panel.

There's also support for the disable operation.

Done that by making use of the new emukit features.

The new event driven strategy works better with react.

The solution makes use of the chrono module to obtain time and the image module to save PNG files.
The Web version is still pending support for printing.

There's already two drivers implemented: Null and Print (to stdout).