Update DrupalorgVersioncontrolLabelVersionMapperGit for semantic versioning in Drupal 8

This logic will need to be changed:

    // Core versions are totally different from contrib.
    if ($project_node->nid == DRUPALORG_CORE_NID) {
      // Core official versions can be any of the following:
      // 4.7.0-beta3
      // 4.7.0
      // 6.18
      // 7.0-unstable3
      // 7.0
      if (preg_match('/^(\d+)\.(\d+)(\.(\d+))?(-((unstable|alpha|beta|rc)\d+))?$/', $tag_name, $matches)) {
        // Starting with version 5, we only have 2 digits, major and patch.
        if ($matches[1] >= 5) {
          $version->version_major = $matches[1];
          $version->version_patch = $matches[2];
          $api_term = $version->version_major . '.x';
        }
        // Prior to 5, we had all 3: major, minor and patch.
        else {
          $version->version_major = $matches[1];
          $version->version_minor = $matches[2];
          // Match 4 contains the patch level without the leading '.'.
          $version->version_patch = $matches[4];
          $api_term = $version->version_major . '.' . $version->version_minor . '.x';
        }
        // Match 6 contains the version extra without the leading '-'.
        if (!empty($matches[6])) {
          $version->version_extra = $matches[6];
        }
      }
    }

The change might be as simple as adding && $matches[1] <= 7 to $matches[1] >= 5, and updating all the comments.