the composer will now count only significant whitespaces

updated the composer reply length counting procedure to take into account only significant whitespaces in order to match the preview.

### before

![Screenshot_13_03_13_00_00-2](https://f.cloud.github.com/assets/362783/251542/43123f1a-8b69-11e2-9c17-9a9c85ffc352.png)

### after

![Screenshot_13_03_13_00_05](https://f.cloud.github.com/assets/362783/251549/69c6a9c0-8b69-11e2-9dec-57de67ce769d.png)