#297 Update api_functionlist, add new functions (hdf5-1.8.12-snap2)

!!! To have the tests running 'hdf5-1.8.12-snap2' is needed !!!

api_types_hdf5.pxd and api_functions.txt have been updated to the newest header files hdf5.h version hdf5-1.8.12-snap2

further the changes provides a python script: 
c2py.py to easy check changes of the hdf5.h-API.
c2py.py is not needed to build, but is very helpfull to check API changes and new, not yet used functions of the hdf5-library.


./c2py.py
usage: c2py.py [-h] [--hdfDir HDFDIR] [--header HEADER] [-v] outFile

Parse the hdf5 header to use for h5py.

generates file: "outFile"
generates file: new.api_functions.txt,  unused.api_functions.txt
generates file: new.api_types_hdf5.pxd, unused.api_types_hdf5.pxd

This will generate the files new.api_functions.txt and new.api_types_hdf5.pxd that can
be compared with the origin h5py-files api_functions.txt and api_types_hdf5.pxd.
The generated "outFile" contains all declared functions, enums and structure
in a readable, condensed format.
the generated files unused.api_functions.txt and unused.api_types_hdf5.pxd contains functions, struct and enums,
that are not yet part of the h5py library.

positional arguments:
  outFile          the file to generate

optional arguments:
  -h, --help       show this help message and exit
  --hdfDir HDFDIR  the hdf directory
  --header HEADER  the header file to parse
  -v               verbose

Example:
  c2py.py -v --hdfDir=../../hdf5/include --header=hdf5py.h c2pyOut.txt

----

In addition to these changes some new functions of the hdf5 version 1.8.12 are added:
New function implemented:
 - chunck_write (H5DOwrite_chunk)