unit tests added, one test still fails because special case of corner touched by meridian or equator not handled correctly, needs test for direction
Merge remote-tracking branch 'origin/master'

Conflicts:
	mms/src/main/java/org/esa/cci/sst/tools/overlap/PolarOrbitingPolygon.java
	mms/src/test/java/org/esa/cci/sst/tools/overlap/PolarOrbitingPolygonTest.java
unit tests added, all tests succeed now after shifting polygon points on the equator or the meridian
merge of Tom's and my concurrent updates of point-in-polygon