Fix specs for avatars

Implement avatar picker
Correct avatar related jobs

app/controllers/user_avatars_controller.rb

@@ -0,0 +1,62 @@
+require_dependency 'letter_avatar'
+
+class UserAvatarsController < ApplicationController
+  skip_before_filter :check_xhr, :verify_authenticity_token, only: :show
+
+  def refresh_gravatar
+
+    user = User.find_by(username_lower: params[:username].downcase)
+    guardian.ensure_can_edit!(user)
+
+    if user
+      user.create_user_avatar(user_id: user.id) unless user.user_avatar
+      user.user_avatar.update_gravatar!
+
+      render json: {upload_id: user.user_avatar.gravatar_upload_id}
+    else
+      raise Discourse::NotFound
+    end
+  end
+
+
+  def show
+    username = params[:username].to_s
+    raise Discourse::NotFound unless user = User.find_by(username_lower: username.downcase)
+
+    size = params[:size].to_i
+    if size > 1000 || size < 1
+      raise Discourse::NotFound
+    end
+
+    image = nil
+    version = params[:version].to_i
+
+    raise Discourse::NotFound unless version > 0 && user_avatar = user.user_avatar
+
+    upload = Upload.find(version) if user_avatar.contains_upload?(version)
+    upload ||= user.uploaded_avatar if user.uploaded_avatar_id == version
+
+    if user.uploaded_avatar && !upload
+      return redirect_to "/avatar/#{user.username_lower}/#{size}/#{user.uploaded_avatar_id}.png"
+    elsif upload
+      # TODO broken with S3 (should retrun a permanent redirect)
+      original = Discourse.store.path_for(upload)
+      if File.exists?(original)
+        optimized = OptimizedImage.create_for(
+          upload,
+          size,
+          size,
+          allow_animation: SiteSetting.allow_animated_avatars
+        )
+        image = Discourse.store.path_for(optimized)
+      end
+    end
+
+    if image
+      expires_in 1.year, public: true
+      send_file image, disposition: nil
+    else
+      raise Discourse::NotFound
+    end
+  end
+end