Merge branch 'jn/gitweb-js'

Merge branch 'jn/gitweb-js'

* jn/gitweb-js:
  gitweb: Make JavaScript ability to adjust timezones configurable
  gitweb.js: Add UI for selecting common timezone to display dates
  gitweb: JavaScript ability to adjust time based on timezone
  gitweb: Unify the way long timestamp is displayed
  gitweb: Refactor generating of long dates into format_timestamp_html
  gitweb.js: Provide getElementsByClassName method (if it not exists)
  gitweb.js: Introduce code to handle cookies from JavaScript
  gitweb.js: Extract and improve datetime handling
  gitweb.js: Provide default values for padding in padLeftStr and padLeft
  gitweb.js: Update and improve comments in JavaScript files
  gitweb: Split JavaScript for maintability, combining on build