* s-tassta.adb (Activate_Tasks): After task creation set state to
Activating, vice Runnable. Initialize Known_Tasks, moved here from
s-taprop.adb (Enter_Task). Set Debug_Event_Activating for debugger.
Set state to Runnable after above.
(Task_Wrapper): Set Debug_Event_Run. In exception block set
Debug_Event_Terminated.
* s-taskin.ads (Task_States): Add new states Activiting and
Activator_Delay_Sleep.
(Bit_Array, Debug_Event_Array): New types.
(Global_Task_Debug_Event_Set: New flag.
(Common_ATCB): New field Debug_Events.