Functions for reading and writing Gadget N-body snapshots. The Gadget code is popular in astronomy for running N-body / hydrodynamical cosmological and merger simulations. To find out more about Gadget see the main distribution page at www.mpa-garching.mpg.de/gadget/
Fixed bug in snap read that meant it didn't work on snapshots with particles in multiple species lists.
Fixed issue that code wouldn't work with mass array being specified per particle. Now it will assign masses to particles based on the header mass information.