Merge pull request #526 from cakephp-fr/master

Update French Docs
[ja] updated plugins
fixed indentation in plugins section
updated CakePackages URL
fixed figure note is duplicated
updated CakePackages URL
Update links to new urls.
Add start of menus.
Add :focus styles.
Add keyboard support for dropdown menus.
Merge pull request #528 from cakephp/top-menus

Move language and versions into top menus.
Escape quote to avoid syntax highlighting error
Merge pull request #529 from kamui545/patch-1

Escape quote to avoid syntax highlighting error
update CakePHP website url
changed github link

download page is no file.
[ja] updated installation and tutorials-and-examples section
fixed reST formatting
fixed wording

"extends" is OOP term.
fixed little wording