Record Maven version and java version used during release.

The release plugin should be able to record the version of Maven and the version of the JDK that were used when the release was done.

For example, the prepare phase could write a file called environment-settings.xml that contains the version of Maven and of Java that were used during the prepare step. This file could look something like this:

 
<environment>
  <maven>
    <version>2.0.8</version>
  </maven>
  <java>
    <version>1.4.2_15</version>
    <vendor>sun</vendor>
  </java>
  <os>
    <name>windows</name>
    ...
  </os>
</environment>

The perform part of the release would then make sure that these settings match when the project is re-built and deployed. There could also be another goal in the release plugin, like "check-environment" that would check that the environment settings match. That goal could be used when trying to rebuild an old release.