ensure lines are aligned right:
```
 7
 8
 9
10
11
12
...
```

issue #418

conflicting css class and bad positioned icon

PHP supports exception stacks since 5.3 so we should use it.
Also Errorhandler is now able to display the stack: #297

make sure all information is displayed
Fixes comment by @creocoder issue #408
https://github.com/yiisoft/yii2/pull/408#issuecomment-18454179