fix(web): issue2551356. Add etag header for not-modified (304) request. When a 304 is returned to a conditional request for a static file, print an ETag for the response. ETag was always sent with a 200 response. This also adds initial support for if-none-match conditional requests for static files. Changes: Refactors the if-modified-since code out to a method. It moves a file stat call from serve_static_file to _serve_file so that an etag can be generated by both serve_static_file and serve_file which call _serve_file. Tests added. This does not test the codepath where serve_file pulls content from the database rather than from a local file on disk. Test mocking _serve_file changed to account for 5th argument to serve_file BREAKING CHANGE: function signature for client.py-Client::_serve_file() now has 5 not 4 parameters (added etag param). Since this is a "hidden" method I am not too worried about it.

syntax: glob

*.orig
*.rej
*~
\#*\#
.\#*
*.swp
*.tmp
*.pyd
*.pyc
*.pyo
build
demo
dist
MANIFEST
roundup.egg-info
_test_*
*.cover
share/doc/roundup/html
doc/FAQ.html
doc/admin_guide.html
doc/announcement.html
doc/customizing.html
doc/design.html
doc/developers.html
doc/features.html
doc/glossary.html
doc/implementation.html
doc/index.html
doc/installation.html
doc/mysql.html
doc/overview.html
doc/postgresql.html
doc/security.html
doc/tracker_templates.html
doc/upgrading.html
doc/user_guide.html
doc/whatsnew-0.7.html
doc/whatsnew-0.8.html
doc/xmlrpc.html
locale/*.mo
locale/*.bak
locale/*.poedit
website/www/_tmp/
website/www/COPYING.txt
website/www/docs
website/www/html/
.pytest_cache