remove borders entirely from fixed navbars

docs/assets/css/bootstrap.css

@@ -4146,6 +4146,11 @@ input[type="submit"].btn.btn-mini {
   margin-bottom: 0;
 }
 
+.navbar-fixed-top .navbar-inner,
+.navbar-fixed-bottom .navbar-inner {
+  border: 0;
+}
+
 .navbar-fixed-top .navbar-inner,
 .navbar-fixed-bottom .navbar-inner {
   padding-right: 0;
@@ -4165,7 +4170,6 @@ input[type="submit"].btn.btn-mini {
 }
 
 .navbar-fixed-top .navbar-inner {
-  border-width: 0 0 1px;
   -webkit-box-shadow: 0 1px 10px rgba(0, 0, 0, 0.1);
      -moz-box-shadow: 0 1px 10px rgba(0, 0, 0, 0.1);
           box-shadow: 0 1px 10px rgba(0, 0, 0, 0.1);
@@ -4176,7 +4180,6 @@ input[type="submit"].btn.btn-mini {
 }
 
 .navbar-fixed-bottom .navbar-inner {
-  border-width: 1px 0 0;
   -webkit-box-shadow: 0 -1px 10px rgba(0, 0, 0, 0.1);
      -moz-box-shadow: 0 -1px 10px rgba(0, 0, 0, 0.1);
           box-shadow: 0 -1px 10px rgba(0, 0, 0, 0.1);

less/navbar.less

@@ -153,6 +153,9 @@
   left: 0;
   z-index: @zindexFixedNavbar;
   margin-bottom: 0; // remove 18px margin for static navbar
+  .navbar-inner {
+    border: 0;
+  }
 }
 .navbar-fixed-top .navbar-inner,
 .navbar-fixed-bottom .navbar-inner {
@@ -161,6 +164,7 @@
   .border-radius(0);
 }
 
+// Reset container width
 .navbar-fixed-top .container,
 .navbar-fixed-bottom .container {
   #grid > .core > .span(@gridColumns);
@@ -170,7 +174,6 @@
 .navbar-fixed-top {
   top: 0;
   .navbar-inner {
-    border-width: 0 0 1px;
     .box-shadow(0 1px 10px rgba(0,0,0,.1));
   }
 }
@@ -179,7 +182,6 @@
 .navbar-fixed-bottom {
   bottom: 0;
   .navbar-inner {
-    border-width: 1px 0 0;
     .box-shadow(0 -1px 10px rgba(0,0,0,.1));
   }
 }