Log Message:
Update ViewVC to 1.1.27:

Version 1.1.27 (released 06-Jun-2019)

  * suppress stack traces (with option to show) (#140)
  * distinguish text/binary/image files by icons (#166, #175)
  * colorize alternating file content lines (#167)
  * link to the instance root from the ViewVC logo (#168)
  * display directory and root counts, too (#169)
  * fix double fault error in standalone.py (#157)
  * support timezone offsets with minutes piece (#176)