Fix "undefined index" warnings on system report page if OPcache is not installed or enabled.
Use get_t() in hook_requirements().
Make disabled OPcache an error and suggest what to do in that case. (And kill one last t().)
Tweak the way multiple back-ends are handled; add a UI for defining back-ends; if none are defined, behave as if PHP is just on the local server. This is kind of a big commit, but it *is* atomic IMO.
Use Drush's cache-clear command to manage the OPcache "cache;" no longer use a custom command for this.
cURL-related improvements: set sane timeout and redirection limits; be more informative when an error happens; don't try to continue if the cURL extension is not installed.
"OPCache" => "OPcache" for consistency (the PHP site uses "OPcache," so that's probably the "official" spelling). Exceptions are made for the class names, since classes play by their own rules. They're loose cannons. TURN IN YOUR GUNS AND BADGES YOU'RE OFF THE FORCE