Docs&refactor/clamp refactor

[wisegod62]

I made a few messy commits and if this gets merged, I think that it should be squashed as well.

I noticed in SLMath.clamp() the min and max values were interchangeable, so I replaced the if else (which I thought was less readable) with getting doubles lower and upper defined by Math.min and Math.max of the two bounds passed to the function. It then compares lower and upper with {@code x}.
I'm not sure if this will have a performance impact but I suggest this change to make the code more readable.

I also changed the javadoc above the function a little: First of all, I replaced "max to min" to "the range defined by {@code min} and {@code max}". I also noted that the order doesn't matter.
I also reflected this interchangeability in the description for arguments {@code.min} and {@code.max}.