Fix PaperScope#install() so classes actually get injected.

src/core/PaperScope.js

@@ -137,12 +137,15 @@ var PaperScope = this.PaperScope = Base.extend(/** @lends PaperScope# */{
 				}
 			});
 		});
-		// Use scope as side-car (= 'this' inside iterator), and have it
-		// returned at the end.
-		return Base.each(this, function(value, key) {
-			if (!(key in this))
-				this[key] = value;
-		}, scope);
+		// Copy over all fields from this scope to the destination.
+		// Do not use Base.each, since we also want to enumerate over
+		// fields on PaperScope.prototype, e.g. all classes
+		for (var key in this) {
+			if (!/^(version|_id|load)/.test(key) && !(key in scope)) {
+				console.log(key);
+				scope[key] = this[key];
+			}
+		}
 	},
 
 	/**

src/paper.js

@@ -127,6 +127,9 @@ var paper = new function() {
 // the first PaperScope and return it, all in one statement.
 // The version for 'dev' of this happens in core/initialize.js, since it depends
 // on sequentiality of include() loading.
+// Mark this object as enumerable, so all the injected classes can be enumerated
+// again in PaperScope#install().
+this.enumerable = true;
 return new (PaperScope.inject(this));
 /*#*/ } // options.version != 'dev'
 };