Added a basic GSON library and used it to implement user settings.
Added save and restore installation targets.
Fixing doxygen configurations.
Ensuring doxygen generated files are cleaned up too.
Fix with regard to the more streamlined version of mishap.hpp
Fix with regard to streamlined mishap.hpp
Fixed tests that break due to changed (improved) error messsages.
Refactored the keywords and precedences used by the common2gnx process into separate files.
Merge branch 'development'