Replace memcached with dalli

dalli is a pure ruby library, so this removes the dependency on the libmemcached C library

Gemfile

@@ -15,7 +15,7 @@ gem 'high_voltage'
 gem 'highline'
 gem 'jquery-rails'
 gem 'mail'
-gem 'memcached'
+gem 'dalli'
 gem 'multi_json'
 gem 'paul_revere'
 gem 'pg'

Gemfile.lock

@@ -73,6 +73,7 @@ GEM
       cucumber (>= 1.1.8)
       nokogiri (>= 1.5.0)
     daemons (1.1.9)
+    dalli (2.3.0)
     database_cleaner (0.9.1)
     delayed_job (3.0.3)
       activesupport (~> 3.0)
@@ -128,7 +129,6 @@ GEM
       i18n (>= 0.4.0)
       mime-types (~> 1.16)
       treetop (~> 1.4.8)
-    memcached (1.4.6)
     method_source (0.8.1)
     mime-types (1.19)
     multi_json (1.3.7)
@@ -254,6 +254,7 @@ DEPENDENCIES
   clearance
   cucumber-rails
   daemons
+  dalli
   database_cleaner
   delayed_job
   delayed_job_active_record
@@ -270,7 +271,6 @@ DEPENDENCIES
   jruby-openssl
   launchy
   mail
-  memcached
   multi_json
   newrelic-redis
   newrelic_rpm

app/middleware/api_v1_depedencies.rb

@@ -1,11 +1,11 @@
-require 'memcached'
+require 'dalli'
 
 class V1MarshaledDepedencies
 
   LIMIT = 250
 
   BadRequest = [404, {}, ["Go away"]]
-  TooMany =    [413, {}, 
+  TooMany =    [413, {},
                 ["Too many gems to resolve, please request less than #{LIMIT}"]]
 
   def data_for(name, ary, cache)
@@ -34,7 +34,7 @@ def data_for(name, ary, cache)
     ary
   end
 
-  CACHE = Memcached.new("localhost:11211")
+  CACHE = Dalli::Client.new("localhost:11211")
 
   def call(env)
     request = Rack::Request.new(env)
@@ -55,14 +55,16 @@ def call(env)
     gems.each do |g|
       begin
         data = cache.get "gem.#{g}"
-        ary += Marshal.load(data)
-      rescue Memcached::NotFound
-        begin
-          data_for g, ary, cache
-        rescue
-          return BadRequest
+        if data
+          ary += Marshal.load(data)
+        else
+          begin
+            data_for g, ary, cache
+          rescue
+            return BadRequest
+          end
         end
-      rescue Memcached::ServerIsMarkedDead
+      rescue Dalli::RingError
         begin
           data_for g, ary, nil
         rescue