Shaders are not copied into build folder
For the very first build, the shaders located at "src/core/graphicsEngine/shaders/shaders" are not copied into the build folder. This is not critical if the user installs openwalnut, because during the installation the files are copied. But for users who run openwalnut from the build folder, the shaders are not found. This produces the errors:
*ERROR [WGEShader (WGECameraVignette-vertex.glsl)] The requested shader "WGECameraVignette-vertex.glsl" does not exist in "/opt/Programme/openwalnut/build/bin/../share/openwalnut/shaders", "/opt/Programme/openwalnut/build/bin/../share/openwalnut/shaders/shaders" or "/opt/Programme/openwalnut/build/bin/../share/openwalnut/shaders".