Function name prefix consistency

Naming conventions defined in #1807 
Fixed on "math" types, as well as a few other things in Core

BoundingSphere.getPlaneDistances -> BoundingSphere.computePlaneDistances
Cartesian[2,3,4].getMaximumComponent -> Cartesian[2,3,4].maximumComponent
Cartesian[2,3,4].getMinimumComponent -> Cartesian[2,3,4].minimumComponent
Cartesian[2,3,4].getMaximumByComponent -> Cartesian[2,3,4].maximumByComponent
Cartesian[2,3,4].getMinimumByComponent -> Cartesian[2,3,4].minimumByComponent
CubicRealPolynomial.realRoots -> CubicRealPolynomial.computeRealRoots
CubicRealPolynomial.discriminant -> CubicRealPolynomial.computeDiscriminant
JulianDate.getTotalDays -> JulianDate.totalDyas
JulianDate.getSecondsDifference -> JulianDate.sedondsDifference
JulianDate.getDaysDifference -> JulianDate.daysDifference
JulianDate.getTaiMinusUtc -> JulianDate.computeTaiMinusUtc
Matrix3.getEigenDecompostion -> Matrix3.computeEigenDecomposition
Occluder.getVisibility -> Occluder.computeVisibility
Occluder.getOccludeePoint -> Occluder.computerOccludeePoint
QuadraticRealPolynomial.discriminant -> QuadraticRealPolynomial.computeDiscriminant
QuadraticRealPolynomial.realRoots -> QuadraticRealPolynomial.computeRealRoots
QuarticRealPolynomial.discriminant -> QuarticRealPolynomial.computeDiscriminant
QuarticRealPolynomial.realRoots -> QuarticRealPolynomial.computeRealRoots
Quaternion.getAxis -> Quaternion.axis
Quaternion.getAngle -> Quaternion.angle
Quaternion.innerQuadrangle -> Quaternion.computeInnerQuadrangle
Rectangle.getSouthwest -> Rectangle.southwest
Rectangle.getNorthwest -> Rectangle.northwest
Rectangle.getSoutheast -> Rectangle.southeast
Rectangle.getNortheast -> Rectangle.northeast
Rectangle.getCenter -> Rectangle.center
CullingVolume.getVisibility -> CullingVolume.computeVisibility