Fixed align_rests option of Formatter to work correctly

align_rests option was not working because line of note_head is not updated when formatting rests
Formatter only updated keyProps, so fixed
and also fixed tests to make it possible to compare between align_rests option on and off

Previous:
![33](https://cloud.githubusercontent.com/assets/2025065/3747875/2ffa8de4-17d4-11e4-9b33-61745f04316c.png)
Updated:
![34](https://cloud.githubusercontent.com/assets/2025065/3747876/30069cd8-17d4-11e4-912f-06531d30d7a7.png)