General CMake cleanup/overhaul
* Enable precompiled headers for all projects
* Move specifications itto separate CMakeLists files
* Add openspace-core as a subdirectory
* Move handle_modules functionality into modules/CMakeLists.txt
* Move handleapplications logic into apps/CMakeLists.txt
* Introduce openspace-module-collection interface library to simplify inclusion of modules in applications
* Turn module initialization into a two-step process to adapt to the new minimal dependency scenario
* Compile time speedup
* Remove circular dependencies between modules and core preventing multithreaded compilation on MSVC
* Build Spice multithreaded and as static library
* Remove dependency from core to module-webbrowser
* Remove unused dependency from kameleon
* Remove additional unnecessary dependencies
* Cleanup volume/kameleon/kameleonvolume modules
* Fix visibility issues. Restrict include paths
* Compile kameleon in parallel
* Other cleanup
* Only copy CEF files from one target (hard-coded to OpenSpace right now)
* Remove unused instrumentation code
* Remove the ability to render AABB for globes as it caused a circular dependency between GlobeBrowsing and Debugging
* Removing compiler and cppcheck warnings
* Turn almost all includes into non-system includes
* Don't warn on deprecrated copy
* Updated submodules
* Improve cmake errors
* Calling doMessageLoopWork more often to increase gui performance
* Introduce frequent callbacks
* Restructure browser update callbacks
* Cleanup cef speedup
* Add flag to toggle updating browser between renderable calls
* CEF should not be used in single process mode
* Update CEF version
* Postbuild step for finding framework from web helper
* Load libcef dynamically to fix issue with CEF update
* Only include dynamic library loader on mac
* Improve keyboard mapping support on MacOS
* Add arrow keys
* Rename manifest
* Fix bug with missing blinking cursor in text fields
* Bump minimum cmake version
* CEF fixes: Runtime and correct helper path
* Be true to actual sandbox compatibility specified by CEF
* Cleanup
