Start c++ version of UI -- port basic shape classes
Implement Point and point-related Shape operations
Start implementing basic widget classes
Add missing license headers
Implement Widget class
Missing license headers
Merge branch 'ui-widgets' into ui-c++
Add event handler stubs
Rename EventSink methods (handleFooBar -> dispatch_foo_bar)
Implement Fill classes
Implement root widget
Add license headers
More work on CSS and style and UI primitives
More porting of stuff from Python to C++
Implement CSS selectors
Add testing framework Catch to the tree
Support for standalone build, fixes for some -Wextras
Whitespace
Much more work on c++-ui
Build tests