More tracing

This adds a couple of tracing features:

• More flexible way to carry more data to sysprof (e.g. type and name of actor)
• More flexible way to have optional but still correctly scoped tracing

It also adds more tracing that uses these:

• Optionally trace the paint of every actor, and record type and name
• Optionally trace the allocation of every actor, and record type and name
• Trace X11 events being processed and their name
• Trace synchronized X11 frame drawing management

Maybe not all of these (esp. the last one is a bit specific), could drop that one if that would be preferred.