Put version number on index.xml

While not the best solution in the world, used maven antrun to replace
version number token on index.xml therefore having site generate with
current version number for dependency.

Also, fixed redirect for maven pom xsd.

Site page index.html will then show this...

<dependencies>
  ...
  <dependency>
    <groupId>org.mybatis.caches</groupId>
    <artifactId>mybatis-ehcache</artifactId>
    <version>1.0.4-SNAPSHOT</version>
  </dependency>
  ...
</dependencies>