Serialize :loadplugins command so that options and commands defined by plugins work properly by default.

common/locale/en-US/repeat.xml

@@ -183,7 +183,7 @@
 <item>
     <tags>:lpl :loadplugins</tags>
     <strut/>
-    <spec>:loadplugins</spec>
+    <spec>:loadplugins <oa>pattern</oa> …</spec>
     <description>
         <p>
             Immediately load all plugins which have yet to be loaded. Because
@@ -194,6 +194,10 @@
             newly installed plugins to be easily loaded without restarting
             &dactyl.appName;. See also <o>loadplugins</o>.
         </p>
+        <p>
+            If <oa>pattern</oa>s are provided, the given regular expressions are
+            used as filters rather than those in <o>loadplugins</o>.
+        </p>
     </description>
 </item>