viewvc: update from 1.1.18 to 1.1.21

New upstream release.

Version 1.1.21 (released 13-Sep-2013)

  * fix markup/annotate exception with Python < 2.7 (issue #527)

Version 1.1.20 (released 24-Apr-2013)

  * fix tab-to-space handling regression in markup view
  * fix regression in root lookup handling (issue #526)

Version 1.1.19 (released 22-Apr-2013)

  * improve root lookup performance (issue #523)
  * new 'max_filesize_kbytes' config option and handling (issue #524)
  * tarball generation improvements:
    - preserve Subversion symlinks in generated tarballs (issue #487)
    - reduce memory usage of tarball generation logic
    - fix double compression of generated tarballs (issue #525)
  * file content handling improvements:
    - expanded support for encoding detection and transcoding (issue #11)
    - fix tab-to-space conversion bugs in markup, annotate, and diff views
    - fix handling of trailing whitespace in diff view
  * add support for timestamp display in ISO8601 format (issue #46)