Update docs, query, and showdown for namespacing

docs/.meteor/packages

@@ -11,3 +11,4 @@ jquery-waypoints
 less
 spiderable
 appcache
+handlebars

packages/jquery/package.js

@@ -2,6 +2,9 @@ Package.describe({
   summary: "Manipulate the DOM using CSS selectors"
 });
 
-Package.on_use(function (api) {
+Package.on_use(function (api, where) {
   api.add_files('jquery.js', 'client');
+
+  api.exportSymbol('$', where);
+  api.exportSymbol('jQuery', where);
 });

packages/showdown/package.js

@@ -13,6 +13,7 @@ Package.on_use(function (api, where) {
   where = where instanceof Array ? where : [where];
 
   api.add_files("showdown.js", where);
+  api.exportSymbol('Showdown', where);
 
   // XXX what we really want to do is, load template-integration after
   // handlebars, iff handlebars was included in the project.