move mixins that generate css to utilities.less with different class names, but the same mixins

docs/assets/css/bootstrap-responsive.css

@@ -8,34 +8,6 @@
  * Designed and built with all the love in the world @twitter by @mdo and @fat.
  */
 
-.clearfix:before,
-.clearfix:after {
-  display: table;
-  line-height: 0;
-  content: "";
-}
-
-.clearfix:after {
-  clear: both;
-}
-
-.hide-text {
-  font: 0/0 a;
-  color: transparent;
-  text-shadow: none;
-  background-color: transparent;
-  border: 0;
-}
-
-.input-block-level {
-  display: block;
-  width: 100%;
-  min-height: 30px;
-  -webkit-box-sizing: border-box;
-     -moz-box-sizing: border-box;
-          box-sizing: border-box;
-}
-
 .hidden {
   display: none;
   visibility: hidden;

docs/assets/css/bootstrap.css

@@ -125,34 +125,6 @@ textarea {
   vertical-align: top;
 }
 
-.clearfix:before,
-.clearfix:after {
-  display: table;
-  line-height: 0;
-  content: "";
-}
-
-.clearfix:after {
-  clear: both;
-}
-
-.hide-text {
-  font: 0/0 a;
-  color: transparent;
-  text-shadow: none;
-  background-color: transparent;
-  border: 0;
-}
-
-.input-block-level {
-  display: block;
-  width: 100%;
-  min-height: 30px;
-  -webkit-box-sizing: border-box;
-     -moz-box-sizing: border-box;
-          box-sizing: border-box;
-}
-
 body {
   margin: 0;
   font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
@@ -5703,6 +5675,17 @@ a.badge:hover {
   color: inherit;
 }
 
+.clear:before,
+.clear:after {
+  display: table;
+  line-height: 0;
+  content: "";
+}
+
+.clear:after {
+  clear: both;
+}
+
 .pull-right {
   float: right;
 }
@@ -5723,6 +5706,23 @@ a.badge:hover {
   visibility: hidden;
 }
 
+.text-hide {
+  font: 0/0 a;
+  color: transparent;
+  text-shadow: none;
+  background-color: transparent;
+  border: 0;
+}
+
 .affix {
   position: fixed;
 }
+
+.control-block-level {
+  display: block;
+  width: 100%;
+  min-height: 30px;
+  -webkit-box-sizing: border-box;
+     -moz-box-sizing: border-box;
+          box-sizing: border-box;
+}

less/mixins.less

@@ -9,7 +9,7 @@
 // Clearfix
 // --------
 // For clearing floats like a boss h5bp.com/q
-.clearfix {
+.clearfix() {
   &:before,
   &:after {
     display: table;
@@ -77,7 +77,7 @@
 // CSS image replacement
 // -------------------------
 // Source: https://github.com/h5bp/html5-boilerplate/commit/aa0396eae757
-.hide-text {
+.hide-text() {
   font: 0/0 a;
   color: transparent;
   text-shadow: none;
@@ -125,7 +125,7 @@
 // --------------------------------------------------
 
 // Block level inputs
-.input-block-level {
+.input-block-level() {
   display: block;
   width: 100%;
   min-height: @inputHeight; // Make inputs at least the height of their button counterpart (base line-height + padding + border)

less/utilities.less

@@ -3,7 +3,12 @@
 // --------------------------------------------------
 
 
-// Quick floats
+// Floats
+// -------------------------
+
+.clear {
+  .clearfix();
+}
 .pull-right {
   float: right;
 }
@@ -11,20 +16,35 @@
   float: left;
 }
 
+
 // Toggling content
+// -------------------------
+
 .hide {
   display: none;
 }
 .show {
   display: block;
 }
-
-// Visibility
 .invisible {
   visibility: hidden;
 }
+.text-hide {
+  .hide-text();
+}
+
 
 // For Affix plugin
+// -------------------------
+
 .affix {
   position: fixed;
 }
+
+
+// Forms
+// -------------------------
+
+.control-block-level {
+  .input-block-level();
+}