Hide broken/crashing invert parameter of MLT's composite transition.

Related to #403

data/transitions/composite.xml

@@ -12,7 +12,4 @@
     <parameter type="bool" name="progressive" default="1" min="0" max="1">
         <name>Force Progressive Rendering</name>
     </parameter>
-    <parameter type="bool" name="invert" default="0" min="0" max="1">
-        <name>Invert</name>
-    </parameter>
 </transition>

data/transitions/slide.xml

@@ -15,7 +15,4 @@
         <parameter tag="deinterlace" default="0" type="bool" name="deinterlace" >
             <name>Force Deinterlace Overlay</name>
         </parameter>
-        <parameter tag="invert" default="0" type="bool" name="invert" >
-            <name>Invert</name>
-        </parameter>
 </transition>