Improved wording
Removed ``@author`` from list of allowed annotations
Removed ``@example`` from list of allowed annotations
Removed ``@version`` from list of allowed annotations

Not used anymore after https://github.com/cakephp/cakephp/pull/4561
Moved note about comments in English to new "Language" section
Removed example that makes no sense anymore
Rewritten Commenting Code section of the coding conventions
Added fixes mentioned by @dereuromark
Removed phpcs standard invalid whitespaces

It might be a bit less readable but we shouldn't display code examples that violate our own phpcs standard. ;-/

Most of that code will be copy & pasted by people, who later find their code violate the phpcs CakePHP sniff "Dobule space found".
Merge pull request #1711 from cakephp/2.0-docblock-coding-conventions

2.0 docblock coding conventions
follow #1711