cuSTL: implement Foreach for 2D and 1D

- add ::dim to SphericZone
Add Some BOOST_PP Doc Strings
Update Copyright: Year + Author
Merge pull request #335 from ax3l/topic-cuSTLForEachND

cuSTL: implement Foreach for 2D and 1D
Add PNGwriter dependency
Require libpng 1.2.9+

... which provides png_set_expand_gray_1_2_4_to_8 that will be required soon
from PNGwriter in https://github.com/ax3l/pngwriter/issues/10
Merge pull request #337 from ax3l/doc-png2gas

Add PNGwriter dependency
Merge pull request #338 from ax3l/topic-libPNGdep

Require libpng 1.2.9+
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
Refactor CT->RT Vector, General Half-CT Mapper

- follow up to #335
- satisfy @psychocoderHPC at
  https://github.com/ComputationalRadiationPhysics/picongpu/pull/347/files#r11628952
Fix Interface To linearIndex
Merge pull request #349 from ax3l/topic-refactorRTMapping

Refactor CT->RT Vector, General Half-CT Mapper