Merge branch 'develop' into issue-498

Conflicts:
	src/main/java/org/orekit/estimation/measurements/modifiers/RangeRateTroposphericDelayModifier.java
	src/main/java/org/orekit/estimation/measurements/modifiers/RangeTroposphericDelayModifier.java
	src/main/java/org/orekit/models/earth/MariniMurrayModel.java
	src/test/java/org/orekit/estimation/leastsquares/OrbitDeterminationTest.java
	src/test/java/org/orekit/estimation/sequential/KalmanOrbitDeterminationTest.java
	src/test/resources/orbit-determination/GNSS/od_test_GPS07.in
	src/tutorials/java/fr/cs/examples/estimation/OrbitDetermination.java