Code to read/write merger tree data in a standard format, as defined in the
accompanying paper.

Notes: 

* The Python routines are MUCH simpler than either C or Fortran.  Unless
performance is a real issue, I strongly recommend that you use Python.

* Fortran lacks the higher-level HDF5 driver routines, so I have taken the
  approach of using converter routines to translate Fortran calls to C.
  gfortran makes this really easy (except for strings).

* Strings are the cause of 90% of my coding headaches when developing these
  routines and I still don't understand them:
  + I still have not really worked out how string types in HDF5 translate to
    those in Python.  I have cobbled something together that seems to work but I
    don't understand it.
  + In C/Fortran high level HDF5 routines let you read from tables by column
    name - but you have to list the columns that you want IN THE SAME ORDER as
    they appear in the table, and you had better make sure that you spell them
    correctly (they are case sensitive).  If you get either of these things
    wrong then HDF5 will give no error message but will silently return garbage.
  + Strings in C & Fortran are handled in different ways.  I have written helper
    routines to convert one to the other, but that makes the Fortran code look
    rather messy.  Also, it is easy to forget and that can lead to confusing
    error messages.
- so bascially, if things go wrong, first check whether it is a string-related
  problem.

--------------

Directories:

* data/ - to hold test data

* Docs/ - documentation (to be written)

* CExamples/ - Exmple i/o routines in C

* FortranExamples/ - Example i/o routines in Fortran 95

* Library/ - utility routines used by both C and Fortran

* Paper/ - definition of the data format standard

* PythonExamples/ - Examle i/o routines in Python

Each CodeExamples directory should contain:
* readTree - example program to read a tree in the standard HDF5 format
* dumpTree - example program to write a tree in the standard HDF5 format
* other helper routines.
