Fixes the issue #58
The issue #58 has been fixed

 - Unit tests were written
 - The ability to test QControls were added to the qcubed testing infrastracture
 - The new utility class QCss is introduced. It implements a method to format a number or string in a CSS1 <length> format. Additional methods can be added in a future.
 - The QControlBase patched with QCss usage.
Merge pull request #78 from olegabr/bug-58

Fixes the issue #58