Use Rails conventions for ActiveRecord wheres and orders

When using `where` with a `joins`, you can reference the the join
table as a key in a hash in `where`.

Updated `Mailboxer::Receipt`, `Mailboxer::Notification`, and
`Mailboxer::Conversation` to use this convention where possible.

Also use a symbol and/or a hash for `order` where applicable.

app/models/mailboxer/conversation.rb

@@ -93,7 +93,7 @@ def originator
 
   #First message of the conversation.
   def original_message
-    @original_message ||= messages.order('created_at').first
+    @original_message ||= messages.order(:created_at).first
   end
 
   #Sender of the last message.

app/models/mailboxer/notification.rb

@@ -13,21 +13,21 @@ class Mailboxer::Notification < ActiveRecord::Base
                       :length => { :maximum => Mailboxer.body_max_length }
 
   scope :recipient, lambda { |recipient|
-    joins(:receipts).where('mailboxer_receipts.receiver_id' => recipient.id,'mailboxer_receipts.receiver_type' => recipient.class.base_class.to_s)
+    joins(:receipts).where(:mailboxer_receipts => { :receiver_id  => recipient.id, :receiver_type => recipient.class.base_class.to_s })
   }
   scope :with_object, lambda { |obj|
-    where('notified_object_id' => obj.id,'notified_object_type' => obj.class.to_s)
+    where(:notified_object_id => obj.id, :notified_object_type => obj.class.to_s)
   }
   scope :not_trashed, lambda {
-    joins(:receipts).where('mailboxer_receipts.trashed' => false)
+    joins(:receipts).where(:mailboxer_receipts => { :trashed => false })
   }
   scope :unread,  lambda {
-    joins(:receipts).where('mailboxer_receipts.is_read' => false)
+    joins(:receipts).where(:mailboxer_receipts => { :is_read => false })
   }
   scope :global, lambda { where(:global => true) }
-  scope :expired, lambda { where("mailboxer_notifications.expires < ?", Time.now) }
+  scope :expired, lambda { where("#{Mailboxer::Notification.quoted_table_name}.expires < ?", Time.now) }
   scope :unexpired, lambda {
-    where("mailboxer_notifications.expires is NULL OR mailboxer_notifications.expires > ?", Time.now)
+    where("#{Mailboxer::Notification.quoted_table_name}.expires is NULL OR #{Mailboxer::Notification.quoted_table_name}.expires > ?", Time.now)
   }
 
   class << self

app/models/mailboxer/receipt.rb

@@ -13,13 +13,13 @@ class Mailboxer::Receipt < ActiveRecord::Base
   }
   #Notifications Scope checks type to be nil, not Notification because of STI behaviour
   #with the primary class (no type is saved)
-  scope :notifications_receipts, lambda { joins(:notification).where('mailboxer_notifications.type' => nil) }
-  scope :messages_receipts, lambda { joins(:notification).where('mailboxer_notifications.type' => Mailboxer::Message.to_s) }
+  scope :notifications_receipts, lambda { joins(:notification).where(:mailboxer_notifications => { :type => nil }) }
+  scope :messages_receipts, lambda { joins(:notification).where(:mailboxer_notifications => { :type => Mailboxer::Message.to_s }) }
   scope :notification, lambda { |notification|
     where(:notification_id => notification.id)
   }
   scope :conversation, lambda { |conversation|
-    joins(:message).where('mailboxer_notifications.conversation_id' => conversation.id)
+    joins(:message).where(:mailboxer_notifications => { :conversation_id => conversation.id })
   }
   scope :sentbox, lambda { where(:mailbox_type => "sentbox") }
   scope :inbox, lambda { where(:mailbox_type => "inbox") }
@@ -76,12 +76,8 @@ def move_to_sentbox(options={})
     end
 
     def update_receipts(updates, options={})
-      ids = where(options).map { |rcp| rcp.id }
-      unless ids.empty?
-        sql = ids.map { "#{table_name}.id = ? " }.join(' OR ')
-        conditions = [sql].concat(ids)
-        Mailboxer::Receipt.where(conditions).update_all(updates)
-      end
+      ids = where(options).pluck(:id)
+      Mailboxer::Receipt.where(:id => ids).update_all(updates) unless ids.empty?
     end
   end