[Orekit Developers] big change added to the develop branch

[MAISONOBE Luc <luc.maisonobe@c-s.fr>]

Hi all,

I have merged the big patches contributed by Airbus about issue 484.
This means that from now on, on the develop branch (and also the
dsst-od and the gnss-attitude, which I have updated too), we don't
advertise the OrekitException anymore, as they are unchecked.

This is a very large change, almost all methods signatures and
javadoc have been updated. So please merge the current state of
the develop branch as soon as you can before doing any change in
the code base, otherwise you will have big troubles to merge everything.

Thanks to Yannick and Airbus for this contribution.

best regards,
Luc