* Big testing doc refactor
* Combine all the testing documentation in to one place to make it easier to find
* Convert everything to RST
* Create testing_network guide
* Create testing landing page
* For each section detail "how to run" and "how to extend testing"
* More examples
* Lots more detail
The Python3 dev doc is more general than just modules
* Rename it to make that obvious.
* Move generally applicable Python3 information to the Controller section
* Add a Py3/Py2 section on formatting strings
* Fix code-blocks to highlight as python
* Enhance python3 support page
* Add Python3/Python2 compat note
* developing_modules.rst is now in dev_guide, sync changes and delete the old version
* Cleaner RST & formatted code
* Tidyup roadmaps
* Link to repomerge
* Pull in abadger's fixes From https://github.com/ansible/ansible/compare/docs-code-block-fixes?expand=1
* Clean docsite/rst (apart from ROADMAP
