Create ff-maven-plugin

  * This plugin is a simple facade that provides goals from both the
    dml-maven-plugin and the atomic-maven-plugin.  The idea is that
    programmers using the Fenix Framework should only need to use this plugin.
    The goals it provides have the same name as the goals that already
    existed, but with the `ff-` prefix.  Currently, there are the following
    goals:

      * ff-generate-domain
      * ff-post-compile
      * ff-process-atomic-annotations
      * ff-test-generate-domain
      * ff-test-post-compile
      * ff-test-process-atomic-annotations

   * There is some redundancy in that the new adapter Mojos, created in the
     ff-maven-plugin, need to declare the same parameters as the ones that
     they extend.  This can be avoided by building our Mojos using Java 5
     annotations for plugin parameters instead of the Javadoc annotations
     (http://jira.codehaus.org/browse/MPLUGIN-189).

   * Add pt.ist.fenixframework.core.ProcessAtomicAnnotations

   * Update README.md to reflect the latest changes.