Made speed of most of battle animations time-based

- speed of creature-related animation no longer depends on framerate
- most of values from cranim.txt are now used correctly
- removed BMPPalette struct in favor of SDL_Color
- animation group "DEAD" that is used to display dead stacks, by default consists from last frame of "DEATH" group

Notes:
- animation speed may still need some adjustments
- range of config property "battle/animationSpeed" has been changed. This may result in extremely fast animation. To fix - change animation speed via options.

client/gui/CIntObjectClasses.cpp

@@ -546,12 +546,14 @@ CHighlightableButtonsGroup::~CHighlightableButtonsGroup()
 
 void CHighlightableButtonsGroup::select(int id, bool mode)
 {
-	CHighlightableButton *bt = nullptr;
+	assert(!buttons.empty());
+
+	CHighlightableButton *bt = buttons.front();
 	if(mode)
 	{
-		for(size_t i=0;i<buttons.size() && !bt; ++i)
-			if (buttons[i]->ID == id)
-				bt = buttons[i];
+		for(auto btn : buttons)
+			if (btn->ID == id)
+				bt = btn;
 	}
 	else
 	{