Dynamic thread testing

1. Design has three modules in UT level, Transmit sends data from the array in 
   an autonmous thread, interface receives data and passes it on to the display
   block.
         ___________          ___________          ___________
        |           |        |           |        |           |
        | Transmit  |--------| Interface |--------|  Display  | 
        |___________|        |___________|        |___________|
        
 
2. Interface block has one slave thread sensitive to input and transfer data to 
   the display block. The slave thread also creates parent & child thread process. 

3. The display block displays the data sent.

   Also, the time is represented in the new notaion of sc_time. The data is 
   transmitted at each clock edge, which has a period of 5 time units, and a 
   duty cycle of 0.5, and start-offset of zero. Each clock-edge generates a 
   new data. 
   
A result of this test case is also available in result.log file, which illustrates
the sequence of operation such as Interface block waiting for an event notification,
when the transmit block sends data at every clock edge, the interface block passes 
the same to display block & we see that sucessful receiving of data in the display 
block. It also points the invoking of parent & child process.
        
Testing
-------

Have a thread in waiting, sc_start_thread, sc_stop_thread and
sc_kill_thread are all ineffctive

Background 
----------

Dynamical handling of 
  parent-child thread creation, 
  stop thread, 
  kill thread. 
  
The dynamically threads have no sensitivity.

sc_get_thread_pid() : 
    return the current functions process id.  Process id need not be an
    integer value.  It might be a class.

sc_start_thread(pid) :
    move the process specified in the pid to the runnable list.
    If the 'pid' is the same as the running process then the call 
    has no affect.  The call has no effect on waiting processess.

sc_stop_thread(pid) : 
    move the process from the runnable list to the suspended list. 
    If 'pid' is of the calling process then the process stops immediately.  
    It has no affect on waiting processess.

sc_create_thread(&pid) : 
    create a thread dynamically just like SC_THREAD and add 
    the process to the suspended list.  An explicit start is required 
    to start the process. 

sc_kill_thread(pid) :
    Kill a thread.  If 'pid' is of the calling thread the process stops 
    immediately.  It has no affect on waiting processess.
