Local modules and other changes

Administrator utilities
Improved media viewer
Enhanced "On this day" module
Changes log enhancement
Provide unified before/after display of changes
Shared notes shifted style from inline to css and added styles for
shared notes to all themes
reinstated custom js module - deleted module in error
Utility module fix bug that removed leading \ character in path
Utility module improve content of email message by using
WT_Mail::auditFooter
Implemented sitemaps
Added custom 404 file