Move galleries to collection, generate map and slideshow on build, stop using loopdir plugin, update templates accordingly

_plugins/gallery.rb

@@ -0,0 +1,27 @@
+module Jekyll
+  class GalleryPage < Page
+        def initialize(site, gallery, layout)
+            @site = site
+            @dir = gallery.url
+            @name = layout + '.html'
+            self.process(@name)
+            self.read_yaml(File.join(site.source, '_layouts'), 'gallery-' + layout + '.html')
+            self.data.merge!( gallery.data)
+            self.data['gallery'] = gallery.url.split('/')[2]
+            self.data['layout'] = 'gallery-' + layout
+        end        
+    end
+
+    class GalleryPageGenerator < Generator
+        def generate(site)
+            site.collections['gallery'].docs.each do |gallery|
+                if gallery.respond_to?('map')
+                    site.pages << GalleryPage.new(site, gallery, 'map')
+                end
+                if !gallery.respond_to?('slideshow')
+                    site.pages << GalleryPage.new(site, gallery, 'slideshow')
+                end
+            end
+        end
+    end
+end