Change Parameter to IntParameter, FloatParameter, BoolParameter and...

Change Parameter to IntParameter, FloatParameter, BoolParameter and StrParameter (fix bug with None and with number parameter operators).

src/jflow/workflow.py

@@ -157,7 +157,7 @@ class Workflow(threading.Thread):
     
     def add_parameter(self, name, help, default=None, type=types.StringType, choices=None, 
                       required=False, flag=None, group="default", display_name=None, add_to=None):
-        new_param = Parameter(name, help, flag=flag, default=default, type=type, choices=choices, 
+        new_param = ParameterFactory.factory(name, help, flag=flag, default=default, type=type, choices=choices, 
                               required=required, group=group, display_name=display_name)
         # if this input should be added to a particular parameter
         if add_to:
@@ -244,10 +244,10 @@ class Workflow(threading.Thread):
         for param in parameters:
             try: args[param.name] = args[param.name].encode('ascii','ignore')
             except: pass
-            if param.__class__ ==  Parameter:
+            if param.__class__ ==  StrParameter or param.__class__ == IntParameter or param.__class__ == FloatParameter or param.__class__ == BoolParameter:
                 if args[param.name]: default = args[param.name]
                 else: default = param.default
-                new_param = Parameter(param.name, param.help, default=default, type=param.type, choices=param.choices, 
+                new_param = ParameterFactory.factory(param.name, param.help, default=default, type=param.type, choices=param.choices, 
                                       required=param.required, flag=param.flag, group=param.group, display_name=param.display_name)
                 self.__setattr__(param.name, new_param)
             elif param.__class__ == InputFile: