increase mem cache
allow caching of static resources
increase cache limit to one month
leverage browser caching on most pages visible to the average user
remove threadsafe! config call from test environment to fix random failures in travis

Travis is so fast, it manages to get sqlite stuck while testing. Since this never showed
up in production/testing, I assume that this is a rare corner case that’s not worth the
trade off in speed to fix.
include last admin/reviewer change for etags in case questions are updated/remove/etc