Added RealValuedSlider
Tried to implement nicer Slider hierarchy, but is not possible in the way I did it
Revert "Tried to implement nicer Slider hierarchy, but is not possible in the way I did it"

This reverts commit dff8b83f312a91e38bb5287204c83695c78c211e.
Solved bug in RealValuedSlider
Stepped back to status before all the changes which should have resulted in splitting the Slider into more usable pieces.
Merge branch 'master' of https://github.com/happah-graphics/happah