Added header comments to indicate the author(s) of original files.

Suggested by Sergey Sharybin through a code review of the branch.

The information was mostly recovered from the AUTHORS file [1] of the
stand-alone Freestyle package version 2.2.0.

[1] http://freestyle.cvs.sourceforge.net/viewvc/freestyle/freestyle/AUTHORS.TXT

release/scripts/freestyle/style_modules/parameter_editor.py

@@ -16,6 +16,11 @@
 #
 # ##### END GPL LICENSE BLOCK #####
 
+#  Filename : parameter_editor.py
+#  Authors  : Tamito Kajiyama
+#  Date     : 26/07/2010
+#  Purpose  : Interactive manipulation of stylization parameters
+
 import Freestyle
 import math
 import mathutils