<webXML/> tag doesn't work during aggregated build.

When building parent aggregator, subprojects <webXml/> tag uses the wrong base directory (perhaps the base directory of the parent?) to search for the specified web.xml.

<parent>
<groupId>SalesStation</groupId>
<artifactId>SSBuild</artifactId>
<version>SNAPSHOT</version>
<relativePath>../SSBuild/pom.xml</relativePath>
</parent>
<modelVersion>4.0.0</modelVersion>
<groupId>SalesStation</groupId>
<artifactId>SS</artifactId>
<packaging>war</packaging>
<version>SNAPSHOT</version>
<name>SalesStation SS webapp</name>

<build>
<sourceDirectory>WEB-INF/src</sourceDirectory>
<finalName>SS</finalName>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<configuration>
<warSourceDirectory>.</warSourceDirectory>
<excludes>target/**</excludes>
<!-- The ../SS is in there to fix a Maven Bug :o( -->
<webXml>../SS/WEB-INF/maven-web.xml</webXml>
</configuration>
</plugin>