Fix #571 libPMacc limits: 32 bit host

on 32bit hosts, size_t is the same as uint32_t (hopefully)
which declares the `max` for it twice.

Reported by @sigkill on github, thanks!
Update to New Modules on Hypnos
Incooperate Richards Feedback
Replace LWFA Eye Catcher with 3D Img
Add Benjamin Worpitz to Developers
Add Beta-RC6 Changelog
Fix Changelog Typos

thx @PrometheusPI for spotting them
thx @myJetLag for causing them
Fix an other typo, thx @n01r
Bump PIConGPU/png2gas to libSplash 1.2.3+

- makes PIConGPU (and png2gas) write fixed field-sizes (1.2.2+)
  -> should increase performance during writes/reads
- fixes a minor listing bug in libSplash (1.2.3+)
Merge pull request #582 from ComputationalRadiationPhysics/release-beta-rc6

Close #557 Beta-RC6 Release
Hotfix: CMake Boost 1.56.0+ is currently broken
Use CMAKE_BUILD_TYPE for splash2txt

 - use CMAKE_BUILD_TYPE instead of S2T_RELEASE cmake option
 - fix a compile error with gcc 4.9 (uint32_t undefined)
Merge pull request #589 from ComputationalRadiationPhysics/master

Update dev with RC6 release changes
Update splash2txt cmake

 - fix boost warnings
 - add -Wall
Merge pull request #591 from f-schmitt-zih/topic-cmakebuildtype

Fix #554 Use CMAKE_BUILD_TYPE for splash2txt
Merge branch 'dev' of git://github.com/ComputationalRadiationPhysics/picongpu into addTWTSLaser