Changed the UI::Scrollbar class so it doesn't require subclassing and added functionality for horizontal scrollbars. Fixed the textbox and inventory box scrollbars so their lowest point is consistent with the original engine's.
Class members that get properly initialized after the constructor now also get default values during construction to silence warnings. Also fixed a couple of broken entries in response.cpp that were uncovered by these changes.
Removed the BlitType enum and getBlitType() method from RenderObject, and replaced them with setTransparent(). This was done to reduce redundant code, since ManagedSurface can already pick between a transparent and regular blit depending on whether the provided source surface has a transparent color set. Also added the correct transparent color for The Vampire Diaries, and the transparent color for nancy1 now gets calculated on the fly.
The textbox's token parser no longer makes a distinction between captions and responses, and also supports telephone-specific tokens. The code still makes a couple of assumptions about the input text, but those can be fixed in the future if needed.
Rewrote most of the engine using a much more object-oriented approach and using more of ScummVM's common classes. This design deviates quite a lot from the original engine's, but should be more maintainable and extensible in the future.
