Accessing to particle container stored in CUDS-hdf5 file 

This PR proposes a general module for accessing CUDS files stored in a hdf5 file.  This PR illustrates what was proposed on the [wiki at (CUDS_FILE)](https://publicwiki-01.fraunhofer.de/SimPhoNy-Project/index.php/CUDS_File) but this PR only includes work related to particle containers:
* Cuds_File:  module to access the CUDS-hdf5 file 
* FileParticleContainer:  a class to access a specific particle container stored in the CUDS-hdf5 file

I would suggest that `__init__` accepts a pytables file handle and the `open` classmethod takes care of opening the file with the right options (initializing the sections if necessary) and then passing the handle to the constructor.