Design New Update System

JSDelivr and pushing to the master branch then following through to npm, bug fixes and new features could arrive much more quickly and gradually, rather than in one big update (as is done currently).

Proposing still continuing rev15, rev16, rev17 ext. for major increments and new features (we can still push these to master, but an update will only be released in an npm push). A build ID (basically just a random string or Unix timestamp) should be used to differentiate bug fixes and other changes can be viewed in account page as should be set by build.php by find-replace "[[[[BUILDID]]]]" in init.js