Merge pull request #45 from voceconnect/admin_css

add admin css to fix thumbnail overflow. fixes #44. props @Oslaf.

css/multi-post-thumbnails-admin.css

@@ -0,0 +1,4 @@
+img.mpt-thumbnail {
+  width: 100%;
+  height: auto;
+}

multi-post-thumbnails.php

@@ -184,6 +184,8 @@ public function enqueue_admin_scripts( $hook ) {
 				wp_enqueue_script( "mpt-featured-image", $this->plugins_url( 'js/multi-post-thumbnails-admin.js', __FILE__ ), array( 'jquery', 'set-post-thumbnail' ) );
 				wp_enqueue_script( "mpt-featured-image-modal", $this->plugins_url( 'js/media-modal.js', __FILE__ ), array( 'jquery', 'media-models' ) );				
 			}
+
+			wp_enqueue_style( "mpt-admin-css", $this->plugins_url( 'css/multi-post-thumbnails-admin.css', __FILE__ ) );
 		}
 
 		public function admin_header_scripts() {
@@ -394,22 +396,26 @@ private function post_thumbnail_html($thumbnail_id = null) {
 			if ($thumbnail_id && get_post($thumbnail_id)) {
 				$old_content_width = $content_width;
 				$content_width = 266;
-				if ( !isset($_wp_additional_image_sizes["{$this->post_type}-{$this->id}-thumbnail"]))
-					$thumbnail_html = wp_get_attachment_image($thumbnail_id, array($content_width, $content_width));
-				else
-					$thumbnail_html = wp_get_attachment_image($thumbnail_id, "{$this->post_type}-{$this->id}-thumbnail");
+				$attr = array( 'class' => 'mpt-thumbnail' );
+
+				if ( !isset($_wp_additional_image_sizes["{$this->post_type}-{$this->id}-thumbnail"])) {
+						$thumbnail_html = wp_get_attachment_image( $thumbnail_id, array($content_width, $content_width), false, $attr );
+				} else {
+						$thumbnail_html = wp_get_attachment_image( $thumbnail_id, "{$this->post_type}-{$this->id}-thumbnail", false, $attr );
+				}
+
 				if (!empty($thumbnail_html)) {
 					$content = sprintf($set_thumbnail_link, $thumbnail_html);
 					$format_string = '<p class="hide-if-no-js"><a href="#" id="remove-%1$s-%2$s-thumbnail" onclick="MultiPostThumbnails.removeThumbnail(\'%2$s\', \'%1$s\', \'%4$s\');return false;">%3$s</a></p>';
 					$content .= sprintf( $format_string, $this->post_type, $this->id, sprintf( esc_html__( "Remove %s", 'multiple-post-thumbnails' ), $this->label ), $ajax_nonce );
 				}
 				$content_width = $old_content_width;
 			}
-			
+
 			if (version_compare($wp_version, '3.5', '>=')) {
 				$content .= sprintf('<script>%s</script>', $modal_js);
 			}
-			
+
 			return apply_filters( sprintf( '%s_%s_admin_post_thumbnail_html', $this->post_type, $this->id ), $content, $post_ID, $thumbnail_id );
 		}