- Implemented better C++ classes for handling scenes/sources/items in
obs.hpp, allowing them to automatically increment and decrement the
references of each, as well as assign them to QVariants.
- Because QVariants are now using the C++ classes, remove the pointer
QVariant wrapper.
- Use the new C++ classes with the QVariant user data of list box items,
both for the sake of thread safety and to ensure that the data
referenced is not freed until removed. NOTE: still might need some
testing.
- Implemented a source-remove signal from libobs, and start using that
signal instead of the source-destroy signal for signalling item
removal.
