Update to maven-release-plugin 2.5

Fixes a bug causing the release to fail to commit with newer versions of
git.

pom.xml

@@ -376,7 +376,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-release-plugin</artifactId>
-                <version>2.4.1</version>
+                <version>2.5</version>
                 <configuration>
                     <autoVersionSubmodules>true</autoVersionSubmodules>
                     <mavenExecutorId>forked-path</mavenExecutorId>