Moves buttonBackground to mixins (issue 1292)

less/buttons.less

@@ -35,31 +35,6 @@
   }
 }
 
-
-// Mixin for generating button backgrounds
-// ---------------------------------------
-.buttonBackground(@startColor, @endColor) {
-  // gradientBar will set the background to a pleasing blend of these, to support IE<=9
-  .gradientBar(@startColor, @endColor);
-
-  // in these cases the gradient won't cover the background, so we override
-  &:hover, &:active, &.active, &.disabled {
-    background-color: @endColor;
-  }
-
-  // called out separately because IE8 would ignore otherwise
-  &[disabled] {
-    background-color: @endColor;
-  }
-
-  // IE 7 + 8 can't handle box-shadow to show active, so we darken a bit ourselves
-  &:active,
-  &.active {
-    background-color: darken(@endColor, 10%) e("\9");
-  }
-}
-
-
 // Base styles
 // -----------
 

less/mixins.less

@@ -339,6 +339,29 @@
 }
 
 
+// Mixin for generating button backgrounds
+// ---------------------------------------
+.buttonBackground(@startColor, @endColor) {
+  // gradientBar will set the background to a pleasing blend of these, to support IE<=9
+  .gradientBar(@startColor, @endColor);
+
+  // in these cases the gradient won't cover the background, so we override
+  &:hover, &:active, &.active, &.disabled {
+    background-color: @endColor;
+  }
+
+  // called out separately because IE8 would ignore otherwise
+  &[disabled] {
+    background-color: @endColor;
+  }
+
+  // IE 7 + 8 can't handle box-shadow to show active, so we darken a bit ourselves
+  &:active,
+  &.active {
+    background-color: darken(@endColor, 10%) e("\9");
+  }
+}
+
 
 // COMPONENT MIXINS
 // --------------------------------------------------