Allow chaining in the addCrumb method

For convenience I think it might be valuable to allow addCrumb (and possibly other similar functions) to return $this to permit chained calls such as this:

    $this->Html->addCrumb('Admin', '/admin')->addCrumb('Blogs', '/admin/users')->addCrumb('Add');

as opposed to the considerably more verbose version that needs to be used now:

    $this->Html->addCrumb('Admin', '/admin');
    $this->Html->addCrumb('Blogs', '/admin/users');
    $this->Html->addCrumb('Add');

I'm not sure if this violates some API conventions for helpers but it does seem rather more convenient to work with to me.
Update HtmlHelper.php

Updated documentation to include the chained $this return
on `cake acl delete <>` delete all matching records. Makes more sense than deleting one of possibly many.
Fixed CS issues. Fixed bug - added missing condition to find.
No array short syntax in 2.4\!
Merge pull request #3156 from sam-at-github/acl-shell-delete-all

Make `cake acl delete <acl-object>` delete all matching records.
Fix yoda condition in File test
Merge pull request #3186 from bcrowe/hotfix-yoda-test

Fix yoda condition in File test
Adds phpunit required version to TestShell "not found" error message.
Merge pull request #3193 from beporter/feature/phpunit-required-version

Adds phpunit required version to TestShell "not found" error message.
cs
more missing doc block tags added
more cs
fix indentation
correct missed cs errors
Merge pull request #3197 from dereuromark/master-cs

cs
Base model class no longer changes an already defined schemaName value
Sqlserver Datasource how properly appends the schemaName prefix in the describe() method
Change argument type to mixed in docblock, as debug() and pr() accept not just a single type
correct deprecation notices