Update prerequisite to version 2.0.6 (inherited from parent), because we want to use a version of Plexus Utils that is newer than the one used in Maven Core.
Also make sure that the Maven Plugin API is for the same version of Maven.

git-svn-id: https://svn.apache.org/repos/asf/maven/doxia/doxia/trunk@1293623 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/doxia-maven-plugin/pom.xml b/doxia-maven-plugin/pom.xml
index c4fcd5c..9461639 100644
--- a/doxia-maven-plugin/pom.xml
+++ b/doxia-maven-plugin/pom.xml
@@ -37,14 +37,14 @@
   <url>http://maven.apache.org/doxia/doxia/doxia-maven-plugin/</url>
 
   <prerequisites>
-    <maven>2.0.2</maven>
+    <maven>${mavenVersion}</maven>
   </prerequisites>
 
   <dependencies>
     <dependency>
       <groupId>org.apache.maven</groupId>
       <artifactId>maven-plugin-api</artifactId>
-      <version>2.0</version>
+      <version>${mavenVersion}</version>
     </dependency>
     <dependency>
       <groupId>${project.groupId}</groupId>