[FIX] web{site,_editor}: gallery upload image

* when getting the src of an uploaded attachment we have to use src which
  is by default url,

* in a MediaDialog the pager is shared between the document and image
  dialog, but when changing page, it was done for both (even if not
  displayed),

* select the image after uploading it in the ImageDialog.

closes #9284
opw-653061
opw-653167

addons/web_editor/static/src/js/widgets.js

@@ -285,6 +285,9 @@ var ImageDialog = Widget.extend({
             o.id = +o.url.match(/\/web\/content\/([0-9]*)/, '')[1];
         }
         this.parent.$(".pager > li").click(function (e) {
+            if(!self.$el.is(':visible')) {
+                return;
+            }
             e.preventDefault();
             var $target = $(e.currentTarget);
             if ($target.hasClass('disabled')) {
@@ -303,7 +306,6 @@ var ImageDialog = Widget.extend({
             var img = _.select(this.images, function (v) { return v.id == attachment.id;});
             if (img.length) {
                 this.images.splice(this.images.indexOf(img[0]),1);
-                return;
             }
         } else {
             this.images = [];
@@ -421,11 +423,11 @@ var ImageDialog = Widget.extend({
         var $button = this.$('button.filepicker');
         if (!error) {
             $button.addClass('btn-success');
+            this.set_image(attachment);
         } else {
             this.$('form').addClass('has-error')
                 .find('.help-block').text(error);
             $button.addClass('btn-danger');
-            this.set_image(attachment, error);
         }
 
         if (!this.options.select_images) {

addons/website/static/src/js/website.snippets.gallery.js

@@ -232,7 +232,7 @@ options.registry.gallery = options.Class.extend({
         editor.on('saved', this, function (attachments) {
             for (var i = 0 ; i < attachments.length; i++) {
                 var img = $('<img class="img img-responsive mb8 mt8"/>')
-                    .attr("src", attachments[i].url)
+                    .attr("src", attachments[i].src)
                     .attr('data-index', index+i)
                     .data('index', index+i)
                     .appendTo($container);