Merging Mairin's fix for the new user form.

Merging Ravenna's fix for the help_text that were really huge and ugly. ...

Now they are awesome.

Fixed a series of help_text print statements with easier-to-read formatting.

Merging Stylistica's GSoC code, this time the right final branch rather ...

than my accidental merge of the midterm branch.

There's still a problem with hide_address on my end, but in the interest 
of letting stylistica see what I'm seeing while I'm going for lunch at
the hackathon, I'm merging a bit prematurely.

revamp new user form ...

removed default django automatic {{ form.as_p }} and replaced with cleaner, bootstrappy form with nice alignment, etc.

Reverting previous commit, because I merged the wrong branch.

Merging Stylistica's GSoC code. Yeay! ...

There are some outstanding style issues here, but we're going to fix them 
after the fact at Open Source Day rather than beforehand, just to give
participants some easy bugs to find and fix.

Marging Marin's fix

minor correction to html on new user form ...

the majority of fields in this form were outside of the field div, reading the comments in fieldset_forms.py it seems like the whole set of form fields is meant to be in the field div so this tiny patch fixes that for the new user form.

Cleaned up the code, added help-text, simplified the design

Completed adding the 3 types of user preferences

fixed client property in MailmanClientMixin

Adding user's global Mailman preferences

reverting accidentally-committed debug stuff

This will stop failures in list creation from displaying doule error messages

updated news.rst

Added user delete function (given by Varun Sharma)

removed unwanted try except blocks and kwargs from user_delete method

added deleting of user functionality by adding user_delete method in user.py and creating a confirmation page user_confirm_delete.html. This patch will enable the superusers to delete other users.

Changed view comment.

- removed abandoned view function (preferences) ...

- user_mailmansettings is now class-based and lives in views/user.py

DRY up the construction of the Mailman REST Client. Convert API settings to match those of hyperkitty. Given by Richard Wackerbarth and Stephen Turnbull.

Renamed variable in template context to make it more Postorius explicit (given by Richard Wackerbarth).

url conf refactoring. Given by Richard Wackerbarth.

removed unneccessary static url conf for MEDIA

DRY up the construction of the Mailman REST Client ...

Also convert to use the same settings ad those
used by Hyperkitty

Make the context variable more explicitly postorius

Simplify URL definitions by factoring list name

Postorius does not use MEDIA ...

If this functionality is needed, it should be
added from the website urls.py, not here

Slightly improved messages for when the REST API isn't available, telling people to start Mailman core. The wording here could probably use some improvement, but this should be more helpful in the meantime.