redo ago.js, remove therubyracer gem

Gemfile.lock

@@ -79,7 +79,6 @@ GEM
       thor (>= 0.14, < 2.0)
     json (1.8.1)
     kgio (2.9.2)
-    libv8 (3.16.14.3)
     mail (2.5.4)
       mime-types (~> 1.16)
       treetop (~> 1.4.8)
@@ -125,7 +124,6 @@ GEM
     rake (10.2.2)
     rb-readline (0.5.1)
     redcarpet (3.1.1)
-    ref (1.0.5)
     rest-client (1.6.7)
       mime-types (>= 1.16)
     ruby-graphviz (1.0.9)
@@ -146,9 +144,6 @@ GEM
       actionpack (>= 3.0)
       activesupport (>= 3.0)
       sprockets (~> 2.8)
-    therubyracer (0.12.1)
-      libv8 (~> 3.16.14.0)
-      ref
     thor (0.19.1)
     thread_safe (0.3.3)
     tilt (1.4.1)
@@ -188,7 +183,6 @@ DEPENDENCIES
   rest-client
   sanitize
   sass-rails
-  therubyracer
   uglifier
   unicorn
   webrick