Reorganize the contributing docs
[#1384] Make the database query in related_list

* We didn't actually do the database query in related_list if we
  didn't pass a dataset. This commit fixes that.
* Share the dictize function for both cases.
[#1390] Move context definition to prevent exception
[#1393] user_dictize: return apikey correctly

Was returning email instead of apikey. Fixes #1393
[#1392] more fixes from awful commit + tests
[#1392] pep8 fix
Merge branch '1393-bug-user-create-returns-email-for-api-key'
Merge branch 'master' of github.com:okfn/ckan into contributing-docs-reorg

Conflicts:
	CONTRIBUTING.rst
	doc/contributing/coding-standards/css-coding-standards.rst
	doc/index.rst
Replace example good commit message in docs

The example was not actually a very good example, replace it with a
better one from recent git logs.
Another contributing docs reorganization

Redorder it all into a single docs/contributing/ subdirectory with one table
of contents and no sub-sub-directories (except for the frontend guidelines one,
which still needs sorting out). This makes it much easier to see what's there
(one main table of contents for all of contributing) and navigate.

Add _CKAN issue tracker hyperlink target to conf.py.

Move commit messages guidelines to their own page.

Move reviewing a pull request guidelines to their own page.

Fix title style of various titles.

A few other small changes
Fix a Sphinx cross-reference
Add a couple of notes to the documentation guidelines
Merge pull request #1390 from okfn/1390-group_dictize-exception

Exception on group dictize due to 'with_capacity' on context
[#1384] Update related controller to use a list

The controller relied on the output of related_list being a
Query object. Updated them to use the list.
[#1384] Update tests to deal with list

The tests also relied on related_list being a Query instead of
a list. Updated them and added new asserts.
[#1384] Update documentation for related_list

The related_list function should not need an id or dataset
parameter. We use it ourselves in the related dashboard
without an id or dataset parameter.
[#1384] Remove sorted from model_dictize

related_items is already sorted from the database query.
Adding another sorting at the model_dictize level looks
unnecessary and overrides the one from the query.
[#1384] Fix test broken due to sorted change

* Fix the test broken because it expects results from sorted.
* Correct the PEP8 change in related controller.
Merge pull request #1324 from okfn/contributing-docs-reorg

Reorganize the contributing docs
Merge branch '1384-related-list-503'