Add tags support

Set slugify to be global
Update modification date only if text has been changed
Fix a bug in preview (post_id was passed instead of blog_id)
Add Home, Category and Tag links in blog area instead of global area (dynastie template)
Fix a bug in Have_I_right

static/js/dynastie.js

@@ -25,12 +25,7 @@ tinyMCE.init({
 
 });
 
-// From http://planetozh.com/blog/2008/04/javascript-basename-and-dirname/
-function basename(path) {
-    return path.replace(/\\/g,'/').replace( /.*\//, '' );
-}
-
-function previewPost()
+function previewPost(blog_id)
 {
     var w = (screen.width * 80)/100;
     var h = (screen.height * 80)/100;
@@ -39,7 +34,6 @@ function previewPost()
     var form = document.getElementById("previewForm");
     var action = form.action;
     var target = form.target;
-    var blog_id = basename(action);
 
     form.action="/preview/" + blog_id;
     form.target="PreviewPost";