[Section] Add 'props' alias for 'properties'

Closes #299

Author: mpsonntag

odml/section.py

@@ -236,6 +236,12 @@ def properties(self):
         """ The list of all properties contained in this section """
         return self._props
 
+    @property
+    def props(self):
+        """ The list of all properties contained in this section;
+            NIXpy format style alias for 'properties'."""
+        return self._props
+
     @property
     def sections(self):
         """ The list of all child-sections of this section """