Cleaning up less/css.

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

@@ -68,10 +68,3 b' input.ui-button {'
 span#login_widget {
     float: right;
 }
-
-.border-box-sizing {
-    box-sizing: border-box;
-    -moz-box-sizing: border-box;
-    -webkit-box-sizing: border-box;
-}
-

IPython/frontend/html/notebook/static/notebooks/less/variables.less

@@ -1,11 +1,11 b''
 // Bootstrap customizations specific to this page.
 
-@corner_radius: 4px;
-@notebook_background : white;
-@cell_selected_background: darken(@notebook_background, 2%);
-@cell_background: darken(@notebook_background, 3.2%);
-@border_color: darken(@cell_selected_background, 31%);
-@light_border_color: darken(@cell_selected_background, 17%);
-@borderwidth : 1px;
-@fontBaseColor : black;
-@baseFontSize:			30pt;
+@corner_radius:					4px;
+@notebook_background: 			white;
+@cell_selected_background: 		darken(@notebook_background, 2%);
+@cell_background: 				darken(@notebook_background, 3.2%);
+@border_color:					darken(@cell_selected_background, 31%);
+@light_border_color:			darken(@cell_selected_background, 17%);
+@borderwidth:					1px;
+@fontBaseColor:					black;
+@baseFontSize:					30pt;