Catch 'jav\tascript:alert("XSS")' as a bad URL

The URL checker from html5lib was used as inspiration. As html5lib is
based on the same ideas that browsers (should) use for parsing and
checking, this solution should be much more robust.
Removed 'wagtailsearch.indexed'
Updated deprecation warnings
Fixed bad import
Tabbing from password field goes to Submit
Merge pull request #700 from kaedroho/remove-features-08

Removed 'wagtailsearch.indexed' module and updated deprecation warnings
Use latest_revision_created_at in sitemap gen

Much faster than looking it up manually for every page in the site
Fixed JSON Oembed error on Python 3

=> TypeError: the JSON object must be str, not 'bytes'
Fixed failing oembed tests
Added 0.8 release notes to index
Auto register signals only works on Django 1.7
Wagtail 0.8 is in development
Added failing test
created_at of PageRevisions is now copied on page copy
Added Django 1.7 migration
fix code sample indentation
Merge pull request #721 from jsma/patch-1

Fixed JSON Oembed error on Python 3
Changelog for #721
Release note for #721
Merge pull request #734 from edrex/patch-1

docs: fix code sample indentation