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

issue #131

issue #33
- implemted getScreenSize for linux systems
- tiny adjustments and better naming for console color methods
- color switch in base Controller changed to magic property
- colorized Help command