Fix #267 Valgrind Warnings Uninitialized

Some output in non-live visualization (like png, density)
did depend on uninitialized values.
Cosmetics: Pragma once and Copyright update
Merge pull request #339 from ax3l/fix-pngValgrind

PNG Plugin #267 Valgrind Warnings Uninitialized
Fix #341 PluginConnector

The internal notification std::map could cause notifications in
non-deterministic order due to internal ordering by plugin pointer
which can vary from rank to rank.

The old naming "frequency" was corrected to "period" internally.
Interfaces have still to be renamed.
Merge pull request #342 from ax3l/fix-PluginConnector

Fix #341 PluginConnector
Close #343 Rename to setNotificationPeriod
Merge pull request #344 from ax3l/topic-freqPeriod

Close #343 Rename to setNotificationPeriod
Fix a name bug in pic2xdmf.py
Merge pull request #345 from c-schumann-zih/topic-Pic2xdmfNamebugFix

Topic pic2xdmf namebug fix
add typedef CloudShape

add typedef CloudShape to particle shape to have the option
to use the shape as function and not only the assignment shpe of a
particle shape
add ne charge conservation schema ZigZag

add native and first tuned version of new charge conservation schema
param/unitless change -> add ZigZag

add namespaces and definitions for new current schema ZigZag
cfg file changes
add host impl for float2int_rd
modify shift schema for interpolation
tune zigzag charge deposition
compiletime version for zigzag
zigzag

- with DataBox and no Curor
- forEach with no const operators
Fix computeCurrent Deadlock

- if one of the virtual blocks had no work to do
  (because of an empty frame) the __syncthread() operation
  could cause a deadlock
- computeCurrent kernel: every thread now fetches its own
  frame(s), this was shared over a virtual block with the
  first thread performing the frame load
- the new implementation avoids non-block-global __syncthreads()
  without early returns