c2py parsing hdf5 headerfiles

add c2py parser: Parse the hdf5 c-header to use for h5py.
the main modes are:
- gen: generates files:
     c2pyOut.txt: list of which functions have been found in which header files
     new.api_functions.txt,  unused.api_functions.txt
     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.txt" contains all declared functions, enums and structure
     in a readable, condensed format.
- dup: seeks structs and enums that are declared twice in the *.p* files
- use: seeks structs and enums that are declared in api_function.txt but not used in any *.p* file

rework on the api_gen.py: support for const and other basic types

update api_functions.txt : remove unused functions and update argument names (useed c2py with modes use,dup and gen) 

update api_types_hdf5.pxd removing unused types fixing names, add 'const' support

update types in some *.pxd and *.pxy files to get rid of compiler warnings

add write_chunk() support (new hdf5 function)

The commits are made in a way that also small portions can be added to the main repo.

I hope this time my branch will no go too far out of sync.

Regards and thanks for your great h5py
 Thierry