Fixed #20386 - Introspection problem on Oracle

Made introspection always return a unicode as column name on Oracle.
Thanks aaugustin for review and suggestion to use force_text().
Fixed #20433: Extract catalog compilation code from javascript_catalog view.
Made test introduced in 566e284c pass on Python 3.
Fixed #20402: removed as-limit from uWSGI example.

It can fail in hard-to-diagnose ways.
Fixed #20235 -- Use self.object_list if object_list not present in get_context_data kwargs.

This is so MultipleObjectMixin can be used in the same way as
SingleObjectMixin.
Fixed #13546 -- Easier handling of localize field options in ModelForm
Fixed #20269 -- Adapted PostGIS template create script for CentOS/RHEL

Thanks Stephane Benchimol for the report and the initial script and
mfandreas for the patch.
tests added