correctly link pthread library under W32; thanks to RPeschke for the hint
mark classes as DLLEXPORT where needed; thanks again to RPeschke
this addresses eudaq/eudaq#5 and fixes many issues already
disabled warning #4251 for MSVC which is triggered by many std classes and litters up the output
fixed linker errors with Qt5 under Windows (now building for subsystem console instead of windows)
partially addresses eudaq/eudaq#5
updated documentation for setting up the development environment under windows
Merge branch 'cmake_win32_qt5' of https://github.com/hperrey/eudaq into cmake_win32_qt5