add permission service, refactor map model a bit, add validations

app/models/map.rb

@@ -13,9 +13,11 @@ class Map < ActiveRecord::Base
    #:full => ['940x630#', :png]
   },
   :default_url => 'https://s3.amazonaws.com/metamaps-assets/site/missing-map.png'
-  validates_presence_of :name
-  validates_presence_of :arranged
-  validate_presence_of :permission
+  validates :name, presence: true
+  validates :arranged, presence: true
+  validates :arranged, inclusion: { in: [true, false] }
+  validates :permission, presence: true
+  validates :permission, inclusion: { in: Perm::ISSIONS }
     
   # Validate the attached image is image/jpg, image/png, etc
   validates_attachment_content_type :screenshot, :content_type => /\Aimage\/.*\Z/

app/services/perm.rb

@@ -1,7 +1,8 @@
 class Perm
+  # e.g. Perm::ISSIONS
+  ISSIONS = [:commons, :public, :private]
+
   class << self
-    # e.g. Perm::ISSIONS
-    ISSIONS = [:commons, :public, :private]
   
     def short(permission)
       case permission

config/application.rb

@@ -11,7 +11,7 @@ module Metamaps
     # -- all .rb files in that directory are automatically loaded.
 
     # Custom directories with classes and modules you want to be autoloadable.
-    # config.autoload_paths += %W(#{config.root}/extras)
+    config.autoload_paths << Rails.root.join('app', 'services')
 
     # Only load the plugins named here, in the order given (default is alphabetical).
     # :all can be used as a placeholder for all plugins not explicitly named.