2221 : if-modified-since for the htmlmap pages
Change sitemap to remove caching on if modified since request
Revert "2221 : if-modified-since for the htmlmap pages"

This reverts commit 2b8e6f409da5074c805ec7d21f75f2b0c5376e8a.
Merge pull request #504 from datadryad/atmire-2221

2221 : if-modified-since for the htmlmap pages