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