Do not use less functions in gradient mixins to avoid lessc failures when the...

Do not use less functions in gradient mixins to avoid lessc failures when the color values are not actual color values (eg, they could be placeholders).

plugins/Morpheus/stylesheets/base/mixins.less

@@ -35,7 +35,7 @@
     background-image: -moz-linear-gradient(left, @start-color @start-percent, @end-color @end-percent); // FF 3.6+
     background-image:  linear-gradient(to right, @start-color @start-percent, @end-color @end-percent); // Standard, IE10
     background-repeat: repeat-x;
-    filter: e(%("progid:DXImageTransform.Microsoft.gradient(startColorstr='%d', endColorstr='%d', GradientType=1)",argb(@start-color),argb(@end-color))); // IE9 and down
+    filter: e(%("progid:DXImageTransform.Microsoft.gradient(startColorstr='%d', endColorstr='%d', GradientType=1)",@start-color,@end-color)); // IE9 and down
   }
 
   .vertical(@start-color: #555, @end-color: #333, @start-percent: 0%, @end-percent: 100%) {
@@ -44,7 +44,7 @@
     background-image:  -moz-linear-gradient(top, @start-color @start-percent, @end-color @end-percent); // FF 3.6+
     background-image: linear-gradient(to bottom, @start-color @start-percent, @end-color @end-percent); // Standard, IE10
     background-repeat: repeat-x;
-    filter: e(%("progid:DXImageTransform.Microsoft.gradient(startColorstr='%d', endColorstr='%d', GradientType=0)",argb(@start-color),argb(@end-color))); // IE9 and down
+    filter: e(%("progid:DXImageTransform.Microsoft.gradient(startColorstr='%d', endColorstr='%d', GradientType=0)",@start-color,@end-color)); // IE9 and down
   }
 }