Added means of outputting lost particle tracks
Cleaned up implimentation of track output
Cleaned up Fortran implimentation of track writing and added track.py - a utility for converting binary track files to VTK files.
Merged in latest changes to master
Added comments to write_particle_track subroutine and gave track.py the ability to add multiple tracks to one file.
Made minor edits to implimentation.

Moved particle track subroutines to the output module.  Particle tracks can now be written in any run mode that calls transport.  track.py should correctly handle any number of input particle tracks.
Merged in latest updates to master
Added settings.xml track options and updated docs

Tracks can now be made using the <track> element in settings.xml and the documentation has been updated to include track plotting.
Fixed a typo.
Small fixes

Changed the '-tr' commandline option to '-k'.  Removed redundant 'write_particle_track' call.  Moved particle_track subroutines to their own module.  Layed (commented out) groundwork for particle_track to use output_interface.
Update settings.xml RELAX NG schema for <track>.
Update man page with -k, --track.
Minor fixes.
Merge pull request #1 from paulromano/lost_particle_plotting01

Update man page, RELAX NG schema, and minor fixes
Merged in latest changes to master
Changed commandline flag from -k to -t
Deallocated track_identifiers array
Added groundwork for HDF5 support

Currently there is an indexing error with the HDF write statement.
Implimented HDF5 support.
Switched to consistent use of output_interface