Document TimeHelper::nice takes $format as param

As per the [TimeHelper::nice source code](https://github.com/cakephp/cakephp/blob/master/lib/Cake/Utility/CakeTime.php#L349), it can take $format as param. 

So Document that in the book.
[fr] Folllow #550 in fr/core-libraries/helpers/html.rst

and fix typos
[fr] Fix underlines title and add missing parts in fr/plugins.rst
Remove incorrect 'echo' that results in an error

FormHelper::inputDefaults() returns an array, so its output should not be echoed.
Merge pull request #551 from PhantomWatson/master

Remove incorrect 'echo' that results in error
[fr] Follow #551 delete echo in fr/core-librairies/helpers/form.rst
Update console-and-shells.rst
Merge pull request #552 from TeddyBear06/patch-2

Update console-and-shells.rst
Clarify where code could be placed on components. Closes GH-548.
Fixing errors on french html helper
Update mistakes datasources.rst
Update mistakes datasources.rst
Update datasource.rst
Merge pull request #554 from TeddyBear06/master

Update mistakes for datasources.rst
Fix mark up. (add ':')
[ja] follow up #547
Merge pull request #555 from suzuki/feature/fix-markup

Fix mark up.
Merge pull request #556 from suzuki/feature/ja-follow-547

[ja] follow up #547
[ja] follow up #550
Merge pull request #557 from suzuki/feature/ja-follow-550

[ja] follow up #550