Start migration guide for FormHelper.
Update docs for input().
Move sections around and remove dead sections.

* Move inputs() to the bottom because it is a gross feature.
* Remove sections for methods that do not exist anymore.
Fix title formatting.
Fix invalid meta directive.
Update file docs and update indentation.
Fix typo and add comma
Begin updating blog tutorial
Merge pull request #1114 from cakephp/3.0-form-2

3.0 form 2
Update docs for changes in MergeVariablesTrait.
Update callback docs.
Fix typo, clean up code examples
[fr] Rearrange files and folder to follow en version
Merge pull request #1116 from bcrowe/3.0-blog-models

Begin updating blog tutorial
Fix issues found with pull request #1114
Do some more updates to the formhelper docs.

Start a new section that will be needed.
Add small section on how to change templates.
Add a template list.
Correct grammar.
Document 'targetForeignKey'.