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
Merge pull request #1711 from cakephp/2.0-docblock-coding-conventions

2.0 docblock coding conventions