Make headline images explicit, add asset credits

- related_assets gains a `headline` boolean (DB-enforced: at most one
  per page), replacing "first image by position" as the headline
  rule. A rake task backfills the current first image on every live
  head/draft, so nothing changes visually until an editor changes it.
- The image picker sidebar gets a star toggle reflecting the flag;
  the TinyMCE inline-image picker's badge now reads it too, instead
  of assuming position 0.
- No headline chosen (or none attached) now falls back to the
  gallery-count caption itself becoming the lightbox trigger, instead
  of the gallery being unreachable.
- Assets gain creator, source_url, and license_key (against a new
  config/asset_licenses.yml dictionary). asset_credit renders a
  degrading attribution line, reused as a hidden per-image glightbox
  caption so credit is one click away for every image, not only the
  headline's always-visible one.
- Fixed: asset thumbnails rendered unconditionally regardless of
  whether a real variant exists on disk. Asset#has_variant? checks
  file existence, not content type -- some legacy PDFs have real
  pre-rewrite thumbnails a content-type check would have hidden.
- assets#new/edit rebuilt onto the same node_description/node_content
  layout as assets#show, picking up the three new fields in the
  process.

1 files changed, 24 insertions, 12 deletions

diff --git a/app/views/content/_headline_image.html.erb b/app/views/content/_headline_image.html.erb
index 243be408..c764d22d 100644
--- a/app/views/content/_headline_image.html.erb
+++ b/app/views/content/_headline_image.html.erb
@@ -1,16 +1,28 @@
-<%= link_to(
-  image_tag(@images[0].upload.url(:headline)),
-  @images[0].upload.url,
-  :class => "glightbox",
-  :data  => { :gallery => "page-#{@page.node.id}" }
-) %>
+<% gallery_images = @page.assets.images %>
 
-<% if 1 < @images.length %>
-  <div class="right">
-    <%= "#{@images.length} #{t(:images)}" %>
-  </div>
+<% if @headline_asset %>
+  <%= link_to(
+    image_tag(@headline_asset.upload.url(:headline)),
+    @headline_asset.upload.url,
+    :class => "glightbox",
+    :data  => { :gallery => "page-#{@page.node.id}", :title => @headline_asset.name,
+                :description => "#credit_for_asset_#{@headline_asset.id}" }
+  ) %>
+  <% if gallery_images.size > 1 %>
+    <div class="right"><%= "#{gallery_images.size} #{t(:images)}" %></div>
+  <% end %>
+<% elsif gallery_images.any? %>
+  <%= link_to "#{gallery_images.size} #{t(:images)}, #{t(:open_gallery)}",
+        gallery_images.first.upload.url,
+        :class => "glightbox right",
+        :data  => { :gallery => "page-#{@page.node.id}", :title => gallery_images.first.name,
+                    :description => "#credit_for_asset_#{gallery_images.first.id}" } %>
 <% end %>
 
-<% @images[1..-1].each do |image| %>
-  <%= link_to "", image.upload.url, :class => "glightbox", :style => "display: none", :data => { :gallery => "page-#{@page.node.id}" } %>
+<% gallery_images.each do |image| %>
+  <% next if image == @headline_asset %>
+  <% next if !@headline_asset && image == gallery_images.first %>
+  <%= link_to "", image.upload.url, :class => "glightbox", :style => "display: none",
+        :data => { :gallery => "page-#{@page.node.id}", :title => image.name,
+                   :description => "#credit_for_asset_#{image.id}" } %>
 <% end %>