* changed libopenspace cmake module name to openspace-core
* change mouse button callback to include modifiers
* added some new ghoul initialization from the non-MinVR main.cpp
* Add GLFW as an external dependency for MinVR
* Expose `CMAKE_BUILD_TYPE` to cmake gui (for single configuration generators)
* Use generator expressions to get debug vs release mode
* Fix mac app icon
* Cleanup
* CMake cleanups
* Update current year
* Update copyright header
* Use script to return list of all modules
* Update credits, license and ghoul
* Move SGCT external library from ext/sgct to apps/OpenSpace/ext/sgct
* Remove all GLFW dependencies from openspace-core
* Add MinVR dependency
* Add new executable OpenSpace-MinVR that uses MinVR instead of SGCT
