[Lazarus] TThread.WaitFor blocks the main event loop under Linux

[Michael Schnell]

   introducing again
> a dependency on some external tool.
As another issue (important regarding threads) already discussed is 
dropping the libc interface unit and with that the libc binding in Linux 
(and with that the need of doing thread creation, threadvar 
implementation and Futex stuff in the RTL) this really would be a step 
in the wrong direction.

-Michael