disabile bootstrap's capitalized nav-header

IPython/frontend/html/notebook/static/base/less/page.less

@@ -67,3 +67,7 @@ span#login_widget {
     float: right;
     margin-top: 2px;
 }
+
+.nav-header {
+    text-transform: none;
+}

IPython/frontend/html/notebook/static/style/style.min.css

@@ -34,6 +34,7 @@ span#ipython_notebook img{font-family:Verdana,"Helvetica Neue",Arial,Helvetica,G
 .ui-button .ui-button-text{padding:0.2em 0.8em;font-size:77%;}
 input.ui-button{padding:0.3em 0.9em;}
 span#login_widget{float:right;margin-top:2px;}
+.nav-header{text-transform:none;}
 @font-face{font-family:'FontAwesome';src:url('../components/font-awesome/build/assets/font-awesome/font/fontawesome-webfont.eot?v=3.1.0');src:url('../components/font-awesome/build/assets/font-awesome/font/fontawesome-webfont.eot?#iefix&v=3.1.0') format('embedded-opentype'),url('../components/font-awesome/build/assets/font-awesome/font/fontawesome-webfont.woff?v=3.1.0') format('woff'),url('../components/font-awesome/build/assets/font-awesome/font/fontawesome-webfont.ttf?v=3.1.0') format('truetype'),url('../components/font-awesome/build/assets/font-awesome/font/fontawesome-webfont.svg#fontawesomeregular?v=3.1.0') format('svg');font-weight:normal;font-style:normal;}[class^="icon-"],[class*=" icon-"]{font-family:FontAwesome;font-weight:normal;font-style:normal;text-decoration:inherit;-webkit-font-smoothing:antialiased;*margin-right:.3em;}
 [class^="icon-"]:before,[class*=" icon-"]:before{text-decoration:inherit;display:inline-block;speak:none;}
 .icon-large:before{vertical-align:-10%;font-size:1.3333333333333333em;}