[Bug 792465] Fixed width for search button.

This way, localized text will make it wrap, instead of pushing the
button to the next line. Also tweaked the styling of the text box so
that it stays vertically centered.

media/less/search.less

@@ -125,14 +125,18 @@
 
   .search-form {
     margin-bottom: 40px;
+    position: relative;
 
     .btn {
       float: right;
+      width: 240px;
     }
 
     .searchbox {
-      float: left;
-      margin: 10px 0 0 12px;
+      position: absolute;
+      top: 50%;
+      left: 20px;
+      margin-top: -15px;
       width: 606px;
     }
   }