Addtions to porting_guide_2.4
* deprecated notice for win_package return values
* Added vars plugins, config api, inventory plugins. These were mostly backwards compatible.
Added notes for users and devs to check out new features once i write the 'feature docs' I'll
come back and link to them from here
* Porting Guides for Ansible Versions
Improve the user facing documentation.
Tell people what changes they need to make
* More porting guides
* Link porting guides from TOC
* Link porting guides from CHANGELOG.md
* typo in link
* Review feedback
* Better CHANGELOG links
* Better links
* code blocks
* Minor changes
* Correct links, comment out network section in 2.4
* Typos
* Revert non 2.4 changes
* Add placeholders for other items
* multiple inventory
* Update porting_guide_2.4.rst
* Update porting_guide_2.4.rst
* Update porting_guide_2.4.rst
* Update porting_guide_2.4.rst
* add win_command/win_shell escaping notes
* Added some windows porting info
* Edit for grammar
* Correct links, delete Net Platform Agnostic
* 2.5 link
* Network changes in 2.4
* facts_namespacing was pushed back to 2.5
Due to lack of time we pushed this back to 2.5 so that the facts in the namespace could be shortened.
* Python version
* Remove FIXMEs - move to seperate PR
