Add an optional description to the manifest

pf4j/src/main/java/ro/fortsoft/pf4j/ManifestPluginDescriptorFinder.java

@@ -79,6 +79,13 @@ public class ManifestPluginDescriptorFinder implements PluginDescriptorFinder {
         }
         pluginDescriptor.setPluginId(id);
 
+        String description = attrs.getValue("Plugin-Description");
+        if (StringUtils.isEmpty(description)) {
+        	pluginDescriptor.setPluginDescription("");
+        } else {
+            pluginDescriptor.setPluginDescription(description);
+        }
+
         String clazz = attrs.getValue("Plugin-Class");
         if (StringUtils.isEmpty(clazz)) {
         	throw new PluginException("Plugin-Class cannot be empty");

pf4j/src/main/java/ro/fortsoft/pf4j/PluginDescriptor.java

@@ -25,6 +25,7 @@ import java.util.List;
 public class PluginDescriptor {
 
 	private String pluginId;
+	private String pluginDescription;
     private String pluginClass;
     private PluginVersion version;
     private String provider;
@@ -41,6 +42,13 @@ public class PluginDescriptor {
         return pluginId;
     }
 
+    /**
+     * Returns the description of this plugin.
+     */
+    public String getPluginDescription() {
+        return pluginDescription;
+    }
+
     /**
      * Returns the name of the class that implements Plugin interface.
      */
@@ -82,6 +90,10 @@ public class PluginDescriptor {
         this.pluginId = pluginId;
     }
 
+	void setPluginDescription(String pluginDescription) {
+        this.pluginDescription = pluginDescription;
+    }
+
     void setPluginClass(String pluginClassName) {
         this.pluginClass = pluginClassName;
     }