Fix empty for attribute on labels in Horizontal form

docs/base-css.html

@@ -906,15 +906,15 @@ For example, <code>section</code> should be wrapped as inline.
           <form class="bs-docs-example form-horizontal">
             <legend>Legend</legend>
             <div class="control-group">
-              <label class="control-label" for="">Email</label>
+              <label class="control-label" for="inputEmail">Email</label>
               <div class="controls">
-                <input type="text" placeholder="Email">
+                <input type="text" id="inputEmail" placeholder="Email">
               </div>
             </div>
             <div class="control-group">
-              <label class="control-label" for="">Password</label>
+              <label class="control-label" for="inputPassword">Password</label>
               <div class="controls">
-                <input type="password" placeholder="Password">
+                <input type="password" id="inputPassword" placeholder="Password">
               </div>
             </div>
             <div class="control-group">
@@ -929,15 +929,15 @@ For example, &lt;code&gt;section&lt;/code&gt; should be wrapped as inline.
 <pre class="prettyprint linenums">
 &lt;form class="form-horizontal"&gt;
   &lt;div class="control-group"&gt;
-    &lt;label class="control-label" for=""&gt;Email&lt;/label&gt;
+    &lt;label class="control-label" for="inputEmail"&gt;Email&lt;/label&gt;
     &lt;div class="controls"&gt;
-      &lt;input type="text" placeholder="Email"&gt;
+      &lt;input type="text" id="inputEmail" placeholder="Email"&gt;
     &lt;/div&gt;
   &lt;/div&gt;
   &lt;div class="control-group"&gt;
-    &lt;label class="control-label" for=""&gt;Password&lt;/label&gt;
+    &lt;label class="control-label" for="inputPassword"&gt;Password&lt;/label&gt;
     &lt;div class="controls"&gt;
-      &lt;input type="password" placeholder="Password"&gt;
+      &lt;input type="password" id="inputPassword" placeholder="Password"&gt;
     &lt;/div&gt;
   &lt;/div&gt;
   &lt;div class="control-group"&gt;

docs/templates/pages/base-css.mustache

@@ -843,15 +843,15 @@
           <form class="bs-docs-example form-horizontal">
             <legend>Legend</legend>
             <div class="control-group">
-              <label class="control-label" for="">{{_i}}Email{{/i}}</label>
+              <label class="control-label" for="inputEmail">{{_i}}Email{{/i}}</label>
               <div class="controls">
-                <input type="text" placeholder="{{_i}}Email{{/i}}">
+                <input type="text" id="inputEmail" placeholder="{{_i}}Email{{/i}}">
               </div>
             </div>
             <div class="control-group">
-              <label class="control-label" for="">{{_i}}Password{{/i}}</label>
+              <label class="control-label" for="inputPassword">{{_i}}Password{{/i}}</label>
               <div class="controls">
-                <input type="password" placeholder="{{_i}}Password{{/i}}">
+                <input type="password" id="inputPassword" placeholder="{{_i}}Password{{/i}}">
               </div>
             </div>
             <div class="control-group">
@@ -866,15 +866,15 @@
 <pre class="prettyprint linenums">
 &lt;form class="form-horizontal"&gt;
   &lt;div class="control-group"&gt;
-    &lt;label class="control-label" for=""&gt;{{_i}}Email{{/i}}&lt;/label&gt;
+    &lt;label class="control-label" for="inputEmail"&gt;{{_i}}Email{{/i}}&lt;/label&gt;
     &lt;div class="controls"&gt;
-      &lt;input type="text" placeholder="{{_i}}Email{{/i}}"&gt;
+      &lt;input type="text" id="inputEmail" placeholder="{{_i}}Email{{/i}}"&gt;
     &lt;/div&gt;
   &lt;/div&gt;
   &lt;div class="control-group"&gt;
-    &lt;label class="control-label" for=""&gt;{{_i}}Password{{/i}}&lt;/label&gt;
+    &lt;label class="control-label" for="inputPassword"&gt;{{_i}}Password{{/i}}&lt;/label&gt;
     &lt;div class="controls"&gt;
-      &lt;input type="password" placeholder="{{_i}}Password{{/i}}"&gt;
+      &lt;input type="password" id="inputPassword" placeholder="{{_i}}Password{{/i}}"&gt;
     &lt;/div&gt;
   &lt;/div&gt;
   &lt;div class="control-group"&gt;