Remove fill-rate burning early-Z passes.

Remove heavy early-Z passes from various default rendering effects.
Equates to a 25% FPS gain on Mac (no difference on my Linux box).

(Early-Z is fine in principle, but should use trivial shaders and no
lighting, texturing or fog. In local testing no measurable benefit
was found in even a true early-Z pass)

Effects/landmass.eff

@@ -73,6 +73,8 @@
 				<extension-supported>GL_EXT_geometry_shader4</extension-supported>
 			</and>
 		</predicate>
+        
+        <!--
 		<pass>
 			<lighting>true</lighting>
 			<material>
@@ -118,7 +120,7 @@
 				</internal-format>
 			</texture-unit>
 			<program>
-<!-- 				<vertex-shader n="0">Shaders/include_fog.vert</vertex-shader> -->
+			<vertex-shader n="0">Shaders/include_fog.vert</vertex-shader> 
 				<vertex-shader n="1">Shaders/landmass-g.vert</vertex-shader>
 				<geometry-shader>Shaders/landmass.geom</geometry-shader>
 				<fragment-shader n="0">Shaders/include_fog.frag</fragment-shader>
@@ -149,7 +151,6 @@
 			</uniform>
 			<color-mask type="vec4d">0 0 0 0</color-mask>
 
-			<!-- 	    BEGIN fog include -->
 			<uniform>
 				<name>visibility</name>
 				<type>float</type>
@@ -192,9 +193,9 @@
 					<use>fogtype</use>
 				</value>
 			</uniform>
-			<!-- 			END fog include -->
 		</pass>
-
+    -->
+    
 		<pass>
 			<lighting>true</lighting>
 			<material>

Effects/runway.eff

@@ -121,6 +121,8 @@
         </or>
       </and>
     </predicate>
+    
+    <!--
     <pass>
       <lighting>true</lighting>
       <material>
@@ -144,6 +146,8 @@
       </program>
       <color-mask type="vec4d">0 0 0 0</color-mask>
     </pass>
+        -->
+    
     <pass>
       <lighting>true</lighting>
       <material>

Effects/terrain-default.eff

@@ -148,6 +148,8 @@
         </or>
       </and>
     </predicate>
+    
+    <!--
     <pass>
       <lighting>true</lighting>
       <material>
@@ -170,7 +172,8 @@
         <fragment-shader>Shaders/trivial.frag</fragment-shader>
       </program>
       <color-mask type="vec4d">0 0 0 0</color-mask>
-    </pass>
+    </pass> -->
+        
     <pass>
       <lighting>true</lighting>
       <material>
@@ -485,6 +488,8 @@
         </or>
       </and>
     </predicate>
+    
+    <!--
     <pass>
       <lighting>true</lighting>
       <material>
@@ -507,7 +512,8 @@
         <fragment-shader>Shaders/trivial.frag</fragment-shader>
       </program>
       <color-mask type="vec4d">0 0 0 0</color-mask>
-    </pass>
+    </pass> -->
+        
     <pass>
       <lighting>true</lighting>
       <material>
@@ -735,6 +741,8 @@
         </or>
       </and>
     </predicate>
+    
+    <!--
     <pass>
       <lighting>true</lighting>
       <material>
@@ -773,7 +781,8 @@
         <value type="int">0</value>
       </uniform>
       <color-mask type="vec4d">0 0 0 0</color-mask>
-    </pass>
+    </pass> -->
+    
     <pass>
       <lighting>true</lighting>
       <material>
@@ -961,6 +970,8 @@
         </or>
       </and>
     </predicate>
+    
+    <!--
     <pass>
       <lighting>true</lighting>
       <material>
@@ -1000,6 +1011,8 @@
       </uniform>
       <color-mask type="vec4d">0 0 0 0</color-mask>
     </pass>
+        -->
+        
     <pass>
       <lighting>true</lighting>
       <material>