[Lazarus] Event handling example project

[Michael Schnell]

I did a small example project (in fact an enhancement of the 
example/messages/uasynccall.pas example in the svn).

Same lets you select to test

  - TThread.Synchronize
  - TThread.Queue
  - PostMessage
  - PostThreadMessage
  - SendMessage
  - TForm.Dispatch
  - Application.QueuAsyncCall without parameters    and
  - Application.QueuAsyncCall with parameters

 From
  - A thread
  - A timer event     and
  - A button event

If anybody might be inclined to put this project into the examples 
directory in the svn, I'd be happy to send the code.

-Michael