Due to how parameters were set in
NumericalPropagatorBuilder.buildPropagator(...) all parameters are set to the
last value. This error was not detected by the test cases because the test case
used Cd with an orbit that is not sensitive to drag.

Also fixed for TLEPropagatorBuilder, though it will have no effect since the
builder only supports one parameter.

In PartialDerivativesEquations the velocity is set incorrectly. This causes
force models that depend on velocity, such as drag, to report incorrect
derivatives. Also added a test case to check this bug.

Extracting the LOD correction from EOP is done at TIRF level since a
few months ...

Extracting the pole correction from EOP is done at ITRF level since a
few months ...

This change prevents an error with Java 7 compilers as there is a
conflict between two different static methods in base class and subclass
that have same type erause.

It also prepares another future change where a third derivative can be
optionnaly used in interpolation: linear and angular acceleration.

The warning were due to deprecated methods tested in non-deprecated
tests.

The fix was already applied for regular angular coordinates, it has been
adapted for Field angular coordinates.

Fixes issue #173.

This is Work In Progress.

Fixes issue #173.

Make the code more concise by using a factory method from commons math.

A unit test extracted from the phasing tutorial has been added.

Conflicts:
	src/site/xdoc/changes.xml

The tutorial did have wrong construction parameters ...