Started restart-plugin system
Move hdf5 restart capability to HDF5Writer
Remove unused SimRestartInit. and add comments
Merge branch 'topic-pluginsRestart' into topic-pluginsRestart2

Conflicts:
	src/picongpu/include/plugins/hdf5/HDF5Writer.hpp
Fix testing code
Fix InitPluginNone
Split HDF5Writer into subfiles/classes
Merge pull request #315 from f-schmitt-zih/topic-pluginsRestart2

Topic plugins restart