More Python 3 corrections.

* Change: In unicorn/python/unicornInit.py, when iterating over all the
    loaded modules, now we have "namespace" that have a __file__
    attribute which is set to None. Skip them.
* Change: In stratus1/st_net.py, "is" must be replaced by "==" when
    doing string comparison.
* Change: In stratus1/st_parser.py, open file in "rb" mode instead
    of "r" (so we get a bytestream as now required by Python).

stratus1/src/stratus/st_net.py

@@ -457,13 +457,13 @@ class net :
     cell._TAB_NETS_OUT += [Signal ( "sh_o%d" % num_net, inputNet._arity )]
 
     # Initialisation of shiftType
-    if direction is "left" :
-      if   type is "logical" : shiftType = 0x12
-      elif type is "arith"   : shiftType = 0xa
+    if direction == "left" :
+      if   type == "logical" : shiftType = 0x12
+      elif type == "arith"   : shiftType = 0xa
       else                   : shiftType = 0x6
     else :
-      if   type is "logical" : shiftType = 0x11
-      elif type is "arith"   : shiftType = 0x9
+      if   type == "logical" : shiftType = 0x11
+      elif type == "arith"   : shiftType = 0x9
       else                   : shiftType = 0x5
 
     inst_name = self._st_cell._shift.lower()

stratus1/src/stratus/st_parser.py

@@ -115,7 +115,7 @@ class Parser :
   # Parsing a file
   ################
   def Parse ( self, nameFile ) :
-    self._p.ParseFile ( open ( nameFile, "r" ) )
+    self._p.ParseFile ( open ( nameFile, "rb" ) )
 
 ##################
 class InitParser :

unicorn/python/unicornInit.py

@@ -73,6 +73,7 @@ def unicornConfigure ( **kw ):
             if not 'unicornHook' in module.__dict__:
                 if module.__name__.endswith( '.__pycache__' ): continue
                 if not '__file__' in module.__dict__: continue
+                if module.__file__ is None: continue
                 elements = module.__file__.split( os.sep )
                 if elements[-1] == 'plugins':
                     print( WarningMessage( 'Plugin "{}" do not provides the unicornHook() method, skipped.' \