Lets take another try at a consistent single process mode handling

Revert "dont call settingslogic single process mode, use the hash accessor so it is not required"

This reverts commit 57de9763.

config/initializers/resque.rb

@@ -2,11 +2,11 @@ require 'resque'
 
 Resque::Plugins::Timeout.timeout = 120
 
-if !AppConfig[:single_process_mode] && AppConfig[:redis_url]
+if !AppConfig.single_process_mode? && AppConfig[:redis_url]
   Resque.redis = Redis.new(:host => AppConfig[:redis_url], :port => 6379)
 end
 
-if AppConfig[:single_process_mode]
+if AppConfig.single_process_mode?
   if Rails.env == 'production'
     puts "WARNING: You are running Diaspora in production without Resque workers turned on.  Please don't do this."
   end