Import urljoin from django.utils.six.moves
Import StringIO from django.utils.six.moves
Merge pull request #144 from mmarzantowicz/feature/django-utils-six

Make use of django.utils.six
Fixed: TypeError: initial_value must be str or None, not bytes
DOCO: Added information about usage of HTMLField

Spent quite a bit of time trying to figure out why additional plugins were showing up inside the text editor when using HTMLField. Found out it isn't supported when using this field in this issue:

https://github.com/divio/djangocms-text-ckeditor/issues/72

Decided that I'm not the first person to run into this question, so I'm documenting it for future reference.
Merge pull request #155 from maestrofjp/master

DOCO: Added information about usage of HTMLField
Merge pull request #154 from mmarzantowicz/feature/fix_stringio_error

Fixed: TypeError: initial_value must be str or None, not bytes
django.utils.six supports urlib since 1.5 - we need to do imports the old way
Merge pull request #158 from mmarzantowicz/feature/fix-urlib-for-django-1.4

django.utils.six supports urllib since 1.5 - we need to do imports the old way
Add TEXT_ADDITIONAL_PROTOCOLS setting

html5lib by default restricts what protocols are allowed in links et al.
It also offers a way to extend this list which previously was not
exposed to djangocms_text_ckeditor but can now be manipulated with the
TEXT_ADDITIONAL_PROTOCOLS setting.