* TThread.Terminate does not have any platform specific behavior (it should only set FTerminated to true and call TerminatedSet), thus move it to the platform independant part
Notes:
- Netware had a ThreadSwitch in there, but that is not really required
- some platform were missing the setting of FTerminated to True, thus they'll now do that as well

git-svn-id: trunk@46543 -