Remove unused function arguments and conversion between radians and degrees

[carandraug]

While checking how the rotation is done to add a button for horizontal flip, I noticed this unused arguments and extra computations.

[jburel]

Adding the include flag so it can be part of the daily merge build --include

[joshmoore]

NB: This may well should be considered a breaking change. An alternative would be to replace use of this.r with rotation within the function method. However, as is always the case with an unused argument, someone with the background should likely evaluate what was really intended.

[jburel]

• the conversion changes makes sense
• better to introduce a new function taking 2 arguments and marking the existing correct_rotation as deprecated.

[will-moore]

Since the third argument rotation wasn't being used, it's not a breaking change to remove that argument. Users could still call it with 3 arguments without an error. Also, I wouldn't usually consider methods on a View to be an API that could/would be used externally.

[jburel]

True that js offers "such flexibility" (not sure it is a good thing!)

[jburel]

Thanks