SkeletonAngles: add help button to dialog
Vectors: add method to generate regularly-spaced points on a sphere
Tests: add test for regularly spaced unit vectors
Anisotropy: new public method to calculate in a single sphere
Anisotropy: start counting intercepts from 1 not 0

This avoids a divide by zero error and sets the maximum MIL = radius of
the sampling sphere. Thus, if no intercepts are counted, MIL = radius,
if one intercept is counted, MIL = radius / 2; two intercepts, MIL / 3,
and so on. Images with many intercepts will not be greatly affected, but
anisotropic structures where radius ~= MIL will see greater effects.
Anisotropy: return the same variables as runToStableResult()

To make the API a bit more consistent both public methods return an
Object array containing the DA (wrapped in a one-element double[]), the
coordinates of the MIL rose plot and the Eigendecomposition.
Anisotropy: make sure the sampling sphere is totally inside the image
Anisotropy: throw exception rather than returning null
Anisotropy: add a constant offset of 1 count to the sum of counts

This approach is more accurate than the approach whereby a count of one
was applied to every sampling probe. The current approach means that the
minimum MIL is equal to the total length of probes applied for that
vector, and not the radius of the smaller sampling sphere.
TestDataMaker: add binary noise and plate stacks for testing Anisotropy
Anisotropy: add tests for runToStableResult()
AnisotropyTest: don't display the test image
Anisotropy: add tests for the single-sphere case
Anisotropy: update copyright date range
Anisotropy: implement single sphere mode

In this mode, the MIL is calculated in a single sampling sphere located
at the centre of the stack and reaching to the edges of the stack
SphereFitter: don't run if all points are on the same slice

Also catches the case where slice is not stored due to the ROI Manager
option, Associate ROIs with stack position
Anisotropy: add options to user dialog, with a listener
AnisotropyTest: reduce required precision of anisotropic stable case

Now skipping no-intercept vectors rather than counting as 1
AnisotropyTest: restore precision for anisotropy stable case
Anisotropy: investigate discrepancy between single and multiple spheres

Single spheres too likely to be affected by small features. Need to
generate a grid of parallel vectors centred on the centroid.