specialize GetMPI_StructAsArray

- specialize GetMPI_StructAsArray for static arrays of math::Vector
extend interface of toString()

- add seperator and enclose symbols to .toString()
output energy field components

output field components of E field and B field
fix copy past bug
change example in comment
Merge pull request #447 from psychocoderHPC/topic-refactorEnergyFields

Energy Fields: Componentwise Energy Calc
fix MessageHeader allocation

fix wrong usage of operator new
fix #449 sign unsign compare
Merge pull request #453 from psychocoderHPC/fix-SignUnsignCompares

fix #449 sign unsign compare
Merge pull request #452 from psychocoderHPC/fix-MessageHeaderAllocation

fix message header allocation