Django-stw

Stops browser warnings when used on https websites while not interferring with
sites running on http.

1.0.0 2016-Dec-27 Updates for Django 1.9/1.10 and Python 2.7/3.5

- Old versions of Django/Python are no longer supported.
- Removed shrinkthewebimage template tag since there is no longer and
API distinction between free and Pro accounts.

0.3.0 2013-Feb-08 Removed stwu (secret key) from docs/examples.
Never provide this parameter to STW.

Changes to the shrinkthewebimage template tag:
- The shrinkthewebimage template tag is NOT backward compatible with version
0.0.1. The alt argument is no longer accepted.
- The shrinkthewebimage template tag is now intended for use by free accounts,
it adds the required preview feature. It can also be used by PRO account users
wanting the preview functionality.
- The shrinkthewebimage template tag now accepts PRO key-value arguments
in the same manner as the stwimage tag. This functionality is shown in the
example template but may not yet be fully implemented by the STW web service.

Changes to the stwimage template tag:
- The stwimage can now only be used for PRO features.

Common changes:
- Template tags now throw exceptions in their constructors instead of in the
render function so configuration errors are visible during development.
- django-stw defines a key 'lang' for the SHRINK_THE_WEB dictionary that
can be passed along as a default to the preview tag. Alternately a 'lang'
keyword can be supplied in each template tag invocation. django-stw defaults it
to 'en'. This functionality is not yet implemented by the STW web service.