ported @property phpdoc generator from yii 1.1

fixes #822
Update PHPDoc command to update classfiles automatically
fixed postioning of property tags in php-doc command
phpdoc command skip classes that do not extend Object
fixed indentation of PhpDocController and sort properties alphabetically
refactored code.
updated @property annotations of many classes
Merge branch 'master' of github.com:yiisoft/yii2

* 'master' of github.com:yiisoft/yii2:
  refactored code.
added proper word wrapping and note about read/writeonly properties
allow [] in property doc type
update of @property annotations
added note about differing property types
fixed docs about error methods in Model
finalized PhpDocController

- cleanup API and usage, add documetation link
- introduced @property feature in getter or setter which has precedence
  over @return or @param tag if present
added some class documentation