Move all fixed-timestep render updates to new file RenderFixed.cpp

As part of fixing #464, I'll need to move these pieces of code around
easily. In #220 I just kind of shoved them awkwardly in whatever
fixed function would be last called in the gamestate loop, which I
shouldn't have done as I've now had to make formal fixed-render
functions anyway. Because these fixed functions need to be called
directly before a render function, and I'm fixing the order to put
render functions in their proper place, so I need to be able to move
these around easily, and making them function calls instead of inlined
makes them easier to manipulate.

desktop_version/src/editor.cpp

@@ -3645,11 +3645,9 @@ void editorrender()
     graphics.render();
 }
 
-void editorlogic()
+void editorrenderfixed()
 {
     extern editorclass ed;
-    //Misc
-    help.updateglow();
     graphics.updatetitlecolours();
 
     game.customcol=ed.getlevelcol(ed.levx+(ed.levy*ed.maxwidth))+1;
@@ -3658,27 +3656,6 @@ void editorlogic()
     graphics.setcol(ed.entcol);
     ed.entcolreal = graphics.ct.colour;
 
-    if (game.shouldreturntoeditor)
-    {
-        game.shouldreturntoeditor = false;
-    }
-
-    graphics.titlebg.bypos -= 2;
-    graphics.titlebg.bscroll = -2;
-
-    ed.entframedelay--;
-    if(ed.entframedelay<=0)
-    {
-        ed.entframe=(ed.entframe+1)%4;
-        ed.entframedelay=8;
-    }
-
-    ed.oldnotedelay = ed.notedelay;
-    if(ed.notedelay>0)
-    {
-        ed.notedelay--;
-    }
-
     if (game.ghostsenabled)
     {
         for (size_t i = 0; i < ed.ghosts.size(); i++)
@@ -3726,6 +3703,34 @@ void editorlogic()
     {
         graphics.updatetowerbackground(graphics.titlebg);
     }
+}
+
+void editorlogic()
+{
+    extern editorclass ed;
+    //Misc
+    help.updateglow();
+
+    if (game.shouldreturntoeditor)
+    {
+        game.shouldreturntoeditor = false;
+    }
+
+    graphics.titlebg.bypos -= 2;
+    graphics.titlebg.bscroll = -2;
+
+    ed.entframedelay--;
+    if(ed.entframedelay<=0)
+    {
+        ed.entframe=(ed.entframe+1)%4;
+        ed.entframedelay=8;
+    }
+
+    ed.oldnotedelay = ed.notedelay;
+    if(ed.notedelay>0)
+    {
+        ed.notedelay--;
+    }
 
     if (graphics.fademode == 1)
     {