fix uninitialized array
add uncrustify.cfg to format source code
Use hierarchical groups in libSplash

 - internally group libSplash files, e.g. in fields, particles etc.
Merge pull request #155 from psychocoderHPC/topic-picongpuCodeStileFile

Topic picongpu code stile file
add comment to fix
Merge pull request #149 from psychocoderHPC/fix-GridBufferEventBug

fix uninitialized array
Merge pull request #156 from f-schmitt-zih/topic-hdf5Groups

Use hierarchical groups in libSplash Close #60
Draft for example documentation

- template done
- YAML style
- limits defined