Improved logging and exception messages to aid troubleshooting

Aid the user in troubleshooting configuration issues by improving logging and exception messages such as the "Couldn't find the release 'XYZ' among the supplied releases." MojoExecutionException.

1. Add String representation of found releases to Exception in method org.apache.maven.plugin.changes.ReleaseUtils.getLatestRelease(List<Release>, String)

       throw new MojoExecutionException( "Could not find release [" + pomVersion
             + "] among the supplied releases: " + toString(releases) );
   
       // ... snip ...
   
       public String toString(List<Release> _releases) {
           List<String> releaseStrs = new ArrayList<String>(_releases.size());
           for (Release release : _releases) {
               releaseStrs.add(toString(release));
           }
           return releaseStrs.toString();
       }
   
       public String toString(Release _release) {
           return _release.getClass().getSimpleName()
                   + "[version='" + _release.getVersion() + "'"
                   + ", date='" + StringUtils.defaultString(_release.getDateRelease()) + "'"
                   + ", description='" + StringUtils.defaultString(_release.getDescription()) + "'"
                   + ", totalActions=" + _release.getActions().size()
                   + "]";
       }
   

1. Add debug log to announcement generation:

       public void doGenerate( List<Release> releases ) throws MojoExecutionException
       {
           String version = ( versionPrefix == null ? "" : versionPrefix ) + getVersion();
   
           getLog().debug( "Generating accouncement for version [" + version + "], found releases: " + releaseUtils.toString(releases) );
           doGenerate( releases, releaseUtils.getLatestRelease( releases, version ) );
       }