added dir attribute to html element; made tipsy gravity dependant on that

app/views/invitations/edit.html.haml

 = javascript_include_tag "validation"
 :javascript
   $(function() {
-    $('#user_new [title]').tipsy({trigger: 'focus', gravity: 'w'});
+    $('#user_new [title]').tipsy({trigger: 'focus', gravity: ($('html').attr('dir') == 'rtl') ? 'e' : 'w'});
     $("#user_username").focus();
   });
 

app/views/invitations/new.html.haml

 :javascript
   $(function() {
-    $('#new_user [title]').tipsy({trigger: 'focus', gravity: 'w'});
+    $('#new_user [title]').tipsy({trigger: 'focus', gravity: ($('html').attr('dir') == 'rtl') ? 'e' : 'w'});
     $("#user_email").focus();
   });
 

app/views/layouts/application.html.haml

@@ -3,7 +3,7 @@
 -#   the COPYRIGHT file.
 
 !!!
-%html{:lang => I18n.locale.to_s}
+%html{:lang => I18n.locale.to_s, :dir => (rtl?) ? 'rtl' : 'ltr'}
   %head
     %meta{:charset => 'utf-8'}
 

app/views/layouts/application.mobile.haml

@@ -3,7 +3,7 @@
 -#   the COPYRIGHT file.
 
 !!!
-%html{:lang => I18n.locale.to_s}
+%html{:lang => I18n.locale.to_s, :dir => (rtl?) ? 'rtl' : 'ltr'}
   %head
     %title
       DIASPORA*

app/views/registrations/new.html.haml

@@ -2,7 +2,7 @@
 
 :javascript
   $(function() {
-    $('#user_new [title]').tipsy({trigger: 'focus', gravity: 'w'});
+    $('#user_new [title]').tipsy({trigger: 'focus', gravity: ($('html').attr('dir') == 'rtl')? 'e' : 'w'});
     $("#user_username").focus();
   });
 

public/javascripts/view.js

@@ -152,7 +152,7 @@ var View = {
     addAspect: {
       bind: function() {
         $(".add_aspect_button", "#aspect_nav").tipsy({
-          gravity:"w"
+          gravity: ($('html').attr('dir') == 'rtl')? "e" : "w"
         });
       }
     },