OutputPage: add setCacheOK mmethod
BAC-1251: handle If-None-Match and disable the support of If-Modified-Since
Simplify the check
@prein as c&p detector :)
Merge pull request #2671 from Wikia/bac-1251-if-none-match-support

BAC-1251: handle If-None-Match and disable the support of If-Modified-Since