added SPhysics Class
bugfix in Makefile (multiple object files possible now)
libSPhysics included in Titan Makefile
move() added to SPhysicalObject
added SOrbit to libSPhysics
added cross() to SVector3d and SVector3mp
bugfix SVector3mp
added mpf_t operators to SVector3mp
change to libmpfr
add AreaVelocity calculation to SOrbit
add getter/setter to SPhysicalObject
add SMassPoint