Thread.stop semantics hide errors and throw messages on console

Use of thread.stop0 will only work on java.lang.Thread directly - fix reflection to use the parent class.

Specific cases of this - reported by @mjhagen on lucee channel on Slack... Related to database errors within a scheduled task. Errors on the console are non-descript, and hide the actual error returned from the code. stop0 isn't able to be executed on a TaskThread, so stop() is the only recourse, which sends ThreadDeath instead of the appropriate exception.

May be related to other tickets, i.e.

Pull request #25
https://github.com/lucee/Lucee/pull/25