move all plugin tests out of babel-core and into their appropriate folders

packages/babel-plugin-transform-react-jsx/test/fixtures/react/should-handle-attributed-elements/actual.js

@@ -0,0 +1,11 @@
+var HelloMessage = React.createClass({
+  render: function() {
+    return <div>Hello {this.props.name}</div>;
+  }
+});
+
+React.render(<HelloMessage name={
+  <span>
+    Sebastian
+  </span>
+} />, mountNode);

packages/babel-plugin-transform-react-jsx/test/fixtures/react/should-handle-attributed-elements/expected.js

@@ -0,0 +1,18 @@
+var HelloMessage = React.createClass({
+  displayName: "HelloMessage",
+
+  render: function () {
+    return React.createElement(
+      "div",
+      null,
+      "Hello ",
+      this.props.name
+    );
+  }
+});
+
+React.render(React.createElement(HelloMessage, { name: React.createElement(
+    "span",
+    null,
+    "Sebastian"
+  ) }), mountNode);