Large refactoring of button classes:

- 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

client/gui/CIntObject.cpp

@@ -323,6 +323,19 @@ bool CIntObject::captureThisEvent(const SDL_KeyboardEvent & key)
 	return captureAllKeys;
 }
 
+CKeyShortcut::CKeyShortcut()
+{}
+
+CKeyShortcut::CKeyShortcut(int key)
+{
+	if (key != SDLK_UNKNOWN)
+		assignedKeys.insert(key);
+}
+
+CKeyShortcut::CKeyShortcut(std::set<int> Keys)
+    :assignedKeys(Keys)
+{}
+
 void CKeyShortcut::keyPressed(const SDL_KeyboardEvent & key)
 {
 	if(vstd::contains(assignedKeys,key.keysym.sym)