add rake task for regenerating images

lib/tasks/images.rake

@@ -1,6 +1,23 @@
 require 'danbooru_image_resizer/danbooru_image_resizer'
 
 namespace :images do
+  desc "Regenerates all images for a post id"
+  task :regen => :environment do
+    post_id = ENV["id"]
+
+    if post_id !~ /\d+/
+      raise "Usage: regen_img.rb POST_ID"
+    end
+
+    post = Post.find(post_id)
+    upload = Upload.new
+    upload.file_ext = post.file_ext
+    upload.image_width = post.image_width
+    upload.image_height = post.image_height
+    upload.generate_resizes(post.file_path)
+    post.distribute_files
+  end
+  
   desc "Generate thumbnail-sized images of posts"
   task :generate_preview => :environment do
     Post.where("image_width > ?", Danbooru.config.small_image_width).find_each do |post|