Propagator with time dependent parameters
time dependant parameters
first running version for NL propagator
test case working!
Put dtStable outside of launcher

and modified trajectory: added a zero
initialization and simplified __allocate
All of this so that it can be possible to
define time dependant parametrisation before
stable dt calculation (creating a trajectory
without dt information)
Small modif to kdvParam
Implemented TLM time-dependant

compile, but not tested.
I have to do gradTest also.

<TODO>
It would seem a better approach to merge _pt
propagators with former ones (nDtParam would
then be =1).  It would simplify a lot the
interface.
Possibility to explicitly pass dt to Launcher

(instead of determined by self.dtStable)
Easier when param is time dependant
Fusiones main _pt subroutines
Amended tests routines
All parameters are trajectories - even static ones
Param as Trajectories: modified the rest

There is an issue with kdvSVLauncher.  It was
returning decent SV beforehand, now it's just
numerical instability...
Mainly change in kdvParam (getitem)

and some cosmethic changes here and there...
still looking for the bug in SVLauncher
Version 2.0.0 : time dependant parameters
Optional maxA in kdvLauncher
Merge branch 'paramTraj'