Add the ability for Sliders and their corresponding Screens to have the ability to move in steps greater than 1.
No float support, only the integer screens are affected.
Make sure the Slider can't step in increments of less than 1.
Use integers instead.
Merge pull request #213 from thedax/slider-stepping

Add the ability for integer-based Sliders and their corresponding Screens to have the ability to move in steps greater than 1.