Added flags to use ffi-gosu optionally instead of always trying, made tooltip affected by theme (the last set theme in setup will be used to style the tooltip)

lib/cyberarm_engine/common.rb

@@ -70,6 +70,7 @@ module CyberarmEngine
                    else
                      klass.new(path)
                    end
+
         hash[path] = instance
         asset = instance
       end