Use print() function in both Python 2 and Python 3

Legacy __print__ statements are syntax errors in Python 3 but __print()__ function works as expected in both Python 2 and Python 3.

dedrm_src/config.py

@@ -2,6 +2,7 @@
 # -*- coding: utf-8 -*-
 
 from __future__ import with_statement
+from __future__ import print_function
 
 __license__ = 'GPL v3'
 
@@ -457,7 +458,7 @@ class ManageKeysDialog(QDialog):
 
 class RenameKeyDialog(QDialog):
     def __init__(self, parent=None,):
-        print repr(self), repr(parent)
+        print(repr(self), repr(parent))
         QDialog.__init__(self, parent)
         self.parent = parent
         self.setWindowTitle("{0} {1}: Rename {0}".format(PLUGIN_NAME, PLUGIN_VERSION, parent.key_type_name))