updated notice to state that some included classes are derived from Apache (steps and events handlings interfaces and classes)
updated notice to state that some included classes are derived from Apache
(steps and events handlings interfaces and classes)

CS-SI/Orekit,liscju/Orekit,ProjectPersephone/Orekit,CS-SI/Orekit,Yakushima/Orekit,Yakushima/Orekit,ProjectPersephone/Orekit,petrushy/Orekit,liscju/Orekit,petrushy/Orekit,attatrol/Orekit,wardev/orekit,treeform/orekit,attatrol/Orekit