- save snapshot; refactoring in order to ease NRE development with unified method and dipatch exit. - named debugging cmds __db_* - new cmd __db_run_assertions to perform checking of the internal state
- fixed handling of TclNRRunCallbacks, such that coroutines can be easily used (more testing required) - added temporary routine ::nsf::yieldcheck for coro debugging - renamed Tcl85showStack() to TclShowStack()