~jeffpc/blahgd#5: Respect HTTP_IF_MODIFIED_SINCE

This has the potential of saving a lot of CPU time and network bandwidth.

Logged requests show a variety of values:

 name='HTTP_IF_MODIFIED_SINCE' type=9
     value=''
 name='HTTP_IF_MODIFIED_SINCE' type=9
     value='Tue, 20 Oct 2015 21:24:49 GMT'
 name='HTTP_IF_MODIFIED_SINCE' type=9
     value='Mon, 07 Sep 2015 07:31:05 UTC'

Status: REPORTED
Submitter: ~jeffpc
Assigned to: No-one
Submitted: 1 year, 11 months ago
Updated: 1 year, 11 months ago
Labels: No labels applied.