More documentation fixes

* Use C++ code in C++ comments.
    * `YES`/`NO` to `true`/`false` (e.g. Returns YES if blah blah blah...)
    * Change sample code to C++ code in documents. (see cocos2dx/actions/CCActionTween.h)
    * Function reference (e.g. `setTexture:withRect` to `setTextureWithRect`)

* Removed Hungarian notation from parts of the code.
* Display sample code as code in documentation. (Surround code in document with `code`/`endcode` tags.)
* Fixed tag typo: `deprecatd` -> `deprecated`
* Changed some doc due to the previously changed source code.
* Removed some trailing whitespaces.