Start ADIOS plugin

 - move common hdf5/adios code to new file
 - add adios plugin files
 - add ADIOS to cmake
 - rename hdf5Output.unitless which is common between hdf5/adios
Enable ADIOS output for fields

 - fix ADIOSWriter and subclasses to write field data (no particles yet)
 - add PIC/Adios traits classes
 - remove hdf5 namespace from common CopySpecies.kernel
Enable particles and ghosts for ADIOS

 - enable dumping of particle attributes for real and ghost data
 - update adios traits
Fix adios cmake, free mpi comm and comments
Merge pull request #179 from f-schmitt-zih/topic-adios

ADIOS output support