upstream: Update to raw code of jetpack v2.93
dev_unlinkwpcom:change class.jetpack.php and [slim]jetpack.php to unlink from wp.com
dev_unlinkwpcom:removed photon and devicepx
dev_unlinkwpcom:reload akismet menu while it's active
dev_unlinkwpcom:fix the hidden omnisearch menu bug
dev_unlinkwpcom: rebrand slimjetpack as slim jp in admin pages