Define PaperScope#paper as a reference to the local scope.

And use it to fix Raster JSON example.

examples/JSON/Raster.html

@@ -15,7 +15,7 @@
 	</script>
 	<script type="text/paperscript" canvas="canvas2">
 		window.importJSON = function(json) {
-			project.activate();
+			paper.activate();
 			console.log(json);
 			project.importJSON(json);
 		}

src/core/PaperScope.js

@@ -113,6 +113,18 @@ var PaperScope = Base.extend(/** @lends PaperScope# */{
 		return this._tool;
 	},
 
+	/**
+	 * A reference to the local scope. This is required, so `paper` will always
+	 * refer to the local scope, even when calling into it from another scope.
+	 * `paper.activate();` will have to be called in such a situation.
+	 * @type PaperScript
+	 * @private
+	 * @bean
+	 */
+	getPaper: function() {
+		return this;
+	},
+
 	/**
 	 * The list of available tools.
 	 * @name PaperScope#tools