[fr] updates

-follow #1909
-follow 0533d589
Add example showing how to convert a view variable to a block.

Refs cakephp/cakephp#4973
add getOriginal()
[fr] how to convert a view variable to a block
Merge pull request #1913 from cakephp/issue-4973

Add example showing how to convert a view variable to a block.
Merge pull request #1910 from cakephp/fr-updates

[fr] updates