This file is an empty file in order to test dynamic plugin engine.
For this purpose, we test four part in this engine:
I.   Test path loading engine
II.  Test file loading engine
III. Test registering engine 
IV.  Test dynamic command line engine

I.   Test path loading engine 
    In the dynamic plugin engine, we can add a path to load modules, but this 
  path must be a directory path.So we tempt to add a file path and a unknown 
  path in order to raise errors. We tempt to add a directory path to check if 
  the engine runs.
 
II.  Test file loading engine
    If the path loading engine pass tests, we will make sure that only file with
  extension .cmo and .cmi are loaded by the engine. So we tempt to load files 
  ".cm[oi]" and "<all_names>.cm[oi]<all_names>". I propose to test with empty 
  file to prevent Dynlink error. 
  Warning: with toplevel, loaded files are only .cm[oi] without _gui.cm[oi] 
  files
 
III. Test registering engine
    In this part, we try to register some functions with dynamic engine and
  to apply them. For this purpose, we test with a mutual recursive function
  separated in two files. This test is also an example of how to write a good 
  dynamic plugin.
 
IV.  Test dynamic command line engine
    Similar to the previous part but in this case we test command line 
  registering engine.
