Accept adapter as first argument of Schema constructor

lib/list.js

@@ -59,7 +59,8 @@ function List(data, type, parent) {
 
 var _;
 try {
-    _ = require('underscore');
+    var underscore = 'underscore';
+    _ = require(underscore);
 } catch (e) {
     _ = false;
 }

lib/schema.js

@@ -62,7 +62,10 @@ function Schema(name, settings) {
     // this is only one initialization entry point of adapter
     // this module should define `adapter` member of `this` (schema)
     var adapter;
-    if (name.match(/^\//)) {
+    if (typeof name === 'object') {
+        adapter = name;
+        this.name = adapter.name;
+    } else if (name.match(/^\//)) {
         // try absolute path
         adapter = require(name);
     } else if (existsSync(__dirname + '/adapters/' + name + '.js')) {