graphics optimization feature inspirated by diablo3 engine

* the rendering now consits of two panes
- the background pane (for animated stuff like the map)
- the foreground pane (for steady stuff, like UI)
each pane has it own max FPS and works idependently
this may increase graphics performance on many platforms

src/framework/platform/win32window.cpp

@@ -25,7 +25,6 @@
 #include <framework/application.h>
 #include <framework/thirdparty/apngloader.h>
 #include <framework/core/resourcemanager.h>
-#include <framework/util/utf8.h>
 
 #define HSB_BIT_SET(p, n) (p[(n)/8] |= (128 >>((n)%8)))
 
@@ -305,7 +304,7 @@ void WIN32Window::internalChooseGLVisual()
                                          PFD_TYPE_RGBA,
                                          32,                         // Select Our Color Depth
                                          0, 0, 0, 0, 0, 0,           // Color Bits Ignored
-                                         0,                          // No Alpha Buffer
+                                         1,                          // Alpha Buffer Bits
                                          0,                          // Shift Bit Ignored
                                          0,                          // No Accumulation Buffer
                                          0, 0, 0, 0,                 // Accumulation Bits Ignored

src/framework/platform/x11window.cpp

@@ -371,6 +371,7 @@ void X11Window::internalChooseGLVisual()
 #else
         EGL_RENDERABLE_TYPE, EGL_OPENGL_ES_BIT,
 #endif
+        EGL_ALPHA_SIZE, 1,
         EGL_NONE
     };
 
@@ -386,6 +387,7 @@ void X11Window::internalChooseGLVisual()
     static int attrList[] = {
         GLX_RENDER_TYPE, GLX_RGBA_BIT,
         GLX_DOUBLEBUFFER, True,
+        GLX_ALPHA_SIZE, 1,
         None
     };