Use GWTRepo for Spring4Gwt

See http://www.guj.com.br/1597-maven--spring4gwt-

```
        <dependency>
            <groupId>org.spring4gwt</groupId>
            <artifactId>spring4gwt</artifactId>
            <version>0.0.1</version>
        </dependency>
...
<repository>
      <id>spring4gwt</id>
      <url>http://gwtrepo.googlecode.com/svn/repo/</url>
</repository>
```
