Whitespaces in artifactId or groupId prevent version update

If you have a dependency in your pom that contains whitespaces within the artifactId or groupId the dependency version will not be updated during a release:perform.
This circumstance can occur when you are using code formattors on xml files (pretty print).

<dependencies>
...
<dependency>
<groupId>
de.testpackage
</groupId>
<artifactId>
someartifactId
</artifactId>
<version>2.1.4-SNAPSHOT
</dependency>
...
</dependencies>

The reason is that the org.apache.maven.shared.release.phase.AbstractRewritePomsPhase class does not use the normalize-space xpath function
on the selected tag.
I have attached a patch that is based on revision 556926 (release plugin version 2.0-beta7)