A class that wraps an instance of `CIntObject` creates an area
that users can right click to view information about the creature
they're buying.
The constants were based off the existing ones in the code and were
refined by guessing and checking where clicking falls inside/outside
the border of the rectangle.
* use smart pointers for almost all widget fields
* use SDL2 texture for cursor
* a lot af small tweaks and formatting
* removed CompImage class, it is actually useless as long as regular SDLImage support margins
* CGuiHandler: use smart pointers for [push|pop]Int
* Changed most gui classes to use shared pointers
* Store and use IImage as shared_ptr
* CSpellWindow redesign
* AdventureMapClasses cleanup
* CLabel: store background as smart pointer
* Store CObjectList items as smart pointers
* Removed destroy function of list item
* Store toggle buttons as smart pointers
* Use CComponent as smart pointer
* Attempt to fix artifact merchant drawing
* fixed displaying free upgrades
* do not try to print 3rd or more resource in slot cost (in theory possible with mods)
** we need dynamic gui for that
* CDefEssential--
- renamed CAdventureMapButton to more expectable CButton
- merged CButtonBase into CButton
- created more generic class for clickable elements
- created more generic class for selectable elements
- renamed CHighlightableButton to CToggleButton
- renamed CHighlightableButtonsGrous to CToggleGroup
- minimized differences between API of all these classes
- removed all but one contructors in buttons, with same parameters across all classes
