Merging Dashboard branch that introduces the Dashboard, DashboardItem and moves most of the screen rendering code into a component-based layout that can also be displayed as a screenspace renderable
* Add Onscreen Dashboard
* Add Dashboard class
* Add DashboardItem classes and subclasses
* Added font and fontsize customization to dashboarditems
* Add default dashboard specifications to all scenes
* Add tests.scene to test dashboard items
* Add configuration options to DashboardItemDistance
* Fix distance conversion to correctly use singular or plural values
* Make DashboardItems unique when adding them to a dashboard
* Correctly position test with different font sizes
* Add Dashboard Item that enables spacing between other items
* Add performance measurement to dashboard rendering
* Add method to DashboardItemDistance that computes distance to surface
* Add DashboardItemAngle that computes and prints the angle between three objects
* Add DashboardItemInstruments that shows the instruments on New Horizons
* Add ability to OpenSpaceModules to return a list of Luascripts defined by child objects
* Make it possible for ScreenSpaceDashboard to work with its own dashboard or the main one
Make featured properties and space/time widget easy to disable
Add setting for setting the bounds of the delta time slider
Add exponent to all numerical properties and use where appropriate
Add properties to Guicomponents that collapse the title bar
Add new F2 key to only display the main property window
* Rename OnScreenGui module to ImGui
* Support multiple external module folders (closes#31)
* Cleaning up CMake files
* Restructure application specification
* Add parameter for library mode to all modules
* Add functions to handle global variable state
* Misc/remove warnings (#383)
* Increase build timeout and do a clean rebuild every commit
