Revert "more thread syncs."

This reverts commit 5cd826f91a9ca56eda5cb2abcf073381a618fb56.
Revert "first try for a threaded event dispatcher, but this is not correctly working right now."

This reverts commit fcbef2f039c18c51006d259445e9023cb04bbd5d.
don't use TR_queueEmpty anymore.