missing link addition

Add missing link to model section
Update docs for App::objects() removal.
Create url.rst
Update toc-helpers.rst
Merge pull request #1600 from rapsspider/patch-8

Create url.rst
Merge pull request #1601 from cakephp/remove-app-objects

Update docs for App::objects() removal.
Merge pull request #1595 from antograssiot/patch-1

missing link addition
Fix options in example deleteAll call
actually fix it
Merge pull request #1602 from darxmac/3.0

table-objects, fix deleteAll example
Fix example code.

Refs cakephp/cakephp#4293
Fixed footer paragraph
Merge pull request #1608 from elboletaire/3-0-spanish-translations

3.0 - Fixed conventions footer paragraph (spanish docs)
Fix table class name.
Fix eg. code.
correct model link on index page
Merge pull request #1611 from antograssiot/3.0

3.0 doc correct model link on index page
Merge pull request #1610 from cakephp/3.0-routes-extensions

Fix eg. code.
Shell::param()
Merge pull request #1613 from dereuromark/3.0-shell-param

Shell::param()