Don't start a session if it's known to be empty.

If an app only reads/checks the session there's no need to start a
session to know that the read/checked session value is empty.

Fixes #1981
Avoid code duplication.
Rendering a proper value for html5 attribute 'step'
Using sprintf to convert number into non-scientific notation
Merge pull request #2744 from wnasich/fix_html5_attribute_step

Rendering a proper value for html5 attribute 'step'
Add test to prove Event Manager regression
Check event against listeners registered in local and global manager

Closes #2730
Merge pull request #2740 from rchavik/2.5-event-manager-regression

RFC Fix: CakeEventManager regression
Merge pull request #2693 from ADmad/2.5-session-start

Don't start a session if it's known to be empty.
Merge pull request #2766 from AD7six/2.4.x-bc-form-fix

BC fix for checkbox ids
Added missing 'Session'-Compomnent in bake

If a Controller was baked interactively and one want to use Session flash messages, the required 'Session'-Component wasn't added to the $components-Array
removed indentation
fixed coding standard errors
Fix bake templates to generate functioning code.

Closes #2776
Merge branch 'master' into 2.5
Clarified ACL node lookup failed error.

Original error was ambiguous in stating whether the ARO node lookup failed or the ACO node lookup failed.
Don't return `true` from view classes' render() method.

It cause's Controller:render() to set the response body as `true`.

Refs #2780
Merge pull request #2785 from ADmad/2.4-view-return-value

Don't return `true` from view classes' render() method.
Merge pull request #2782 from jimmymadon/feature-clarify-acl-errors

Clarified ACL node lookup failed error.
Minor documentation corrections about Router::connect().