[MIG] web_widget_float_formula: v9 with i18n

* Update JS to use v9 module system
* Fix non-functioning logic for obtaining the value of an input element
* Eliminate redundant calls (e.g. there were multiple calls to eval)
* Modify formula cleanup to use localized decimal point and thousands separator
 characters
* Add JS unit tests

web_widget_float_formula/tests/__init__.py

@@ -0,0 +1,5 @@
+# -*- coding: utf-8 -*-
+# Copyright 2016 LasLabs Inc.
+# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html).
+
+from . import test_js