The SynthSliderUI#layout method should be splitted in several calculateXXX methods

There are several changes:
1. The SynthSliderUI#layout should be removed (there is no need to add useless methods in the public API)
2. The calculateFocusRect, calculateContentRect, calculateThumbSize etc should be overriden in the SynthSliderUI class and should use functionality from the SynthSliderUI#layout method (otherwise these methods work incorrectly in the SynthSliderUI class)
3. The SynthSliderUI#calculateGeometry method should be removed (this method will not be necessary if we implement item 2)
4. The SynthSliderUI#calculateTickRect should be updated according to the SynthSliderUI#layout method
The SynthSliderUI#layout (item 1) cannot be removed because of it exists in jdk6 already