* 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
* Moved SUMMON_BOAT special case to mechanics
* Partially moved Town portal logic to mechanics class
* Added generic query reply to CCallback
* Redesigned Queries so that base API do not depends on CGameHandler
* Got rid of CGameHandler::castSpellRequest
* Removed CGameHandler::castSpell
* Added new Query type for town portal dialog (not used yet)
* 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--
- implemented switch in settings screen
- implemented "0 speed", animation-free. *may* also work for player-owned heroes
- removed no longer used creature window switch
- 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
