Rotation selector arguments do not allow max to be lower than min

Due to the continuous nature of rotations being interrupted by the sudden switch from negative to positive, it was convenient that those arguments in selectors would be moduloed properly to wrap, so one could do something like this:

/testfor @a[rym=80,ry=-60]

In the current version, the equivalent (/execute if entity @a[y_rotation=80..-60]) fails to build because "the minimum is greater than the maximum." In reality, it is not, because -60 should wrap to what amounts to 300.