Add spring-build 2.5.2

spring-build was previously included via an svn:external. Adding
directly to the source tree under Git to avoid the need for a git
submodule.

In order to build from any earlier commit, it is recommended to
export spring-build or symlink an existing copy into the root
of the spring-framework project and then build normally.

    $ svn export https://src.springsource.org/svn/spring-build/tags/project-build-2.5.2 spring-build

spring-build/multi-bundle/default.xml

@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+   Copyright 2010 SpringSource
+   
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+   
+       http://www.apache.org/licenses/LICENSE-2.0
+   
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+-->
+<project name="default-multi-bundle">
+
+	<import file="common.xml"/>
+	<import file="artifact.xml"/>
+	<import file="quality.xml"/>
+	<import file="package.xml"/>
+	<import file="publish.xml"/>
+
+</project>