Version after 0.7.4, but not 0.7.6, hence 0.7.5.

The previous jacoco plugin version was not compatible with Jenkins
anymore.

This allows for example to retrieve the DEM elevation for a
latitude/longitude pair.

This can be used to set up min/max search lines.

This is still preliminary work, convergence seems slightly wrong.

Conflicts:
	src/test/java/org/orekit/rugged/api/RuggedTest.java