Improve Performance by Avoiding Recalculating Constants

[luckylsk34]

In convertRadiansToDegrees and convertDegreesToRadians methods, we are creating BigDecimals of PI/180 and 180/PI. These values have high precision and BigDecimal is too slow. We move these into a static variable to avoid repeated creations.

This change nets us about 50-66% speedup. The following table contains the testing on my machine.

Index	Total Operations(ops)	Total Time(s)	Speed(ops/s)	Speedup
Default	5,000,000	92	5.43E+04	1.00
Moved to Static Variables	5,000,000	55	9.09E+04	1.67

[luckylsk34]

@mikereedell Hi Mike, please review.