tweaks abound, updated prettify styles, new sidenav component started, sprite icons started

lib/bootstrap.less

@@ -27,6 +27,7 @@
 // Temp catchall for what's missing thus far
 @import "patterns.less";
 
+@import "sprites.less";
 @import "dropdowns.less";
 @import "tabs-pills.less";
 @import "breadcrumbs.less";
@@ -34,6 +35,7 @@
 @import "modals.less";
 @import "twipsy.less";
 @import "popovers.less";
+@import "sidenav.less";
 @import "thumbnails.less";
 
 // Responsive