created tool class which keeps track of cursors, incorporates changeTool; made changelog data its own file

js/tools/_eraser.js

@@ -0,0 +1,13 @@
+
+new Tool('eraser', {
+	cursor: 'crosshair',
+	brushPreview: true,
+});
+
+
+
+new Tool('resizeeraser', {
+	cursor: 'default',
+});
+
+/*global Tool, tool*/