make POSIX and Windows implementation of wxThread::Run() coherently assert when trying to Run() a thread twice; add a test for it.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@65106 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

interface/wx/thread.h

@@ -788,7 +788,7 @@ enum
 
             if (m_pThread)         // does the thread still exist?
             {
-                m_out.Printf("MYFRAME: deleting thread");
+                wxMessageOutputDebug().Printf("MYFRAME: deleting thread");
 
                 if (m_pThread->Delete() != wxTHREAD_NO_ERROR )
                     wxLogError("Can't delete the thread!");
@@ -1125,6 +1125,10 @@ public:
         of detached threads.
 
         This function can only be called from another thread context.
+        
+        Finally, note that once a thread has completed and its Entry() function
+        returns, you cannot call Run() on it again (an assert will fail in debug
+        builds or @c wxTHREAD_RUNNING will be returned in release builds).
     */
     wxThreadError Run();