Forked and heavily modified from alseambusher/crontab-ui.
Really got not much in common with the original - instead of using an internal DB it loads and writes directly to the system crontab for the user it runs as.
Most advanced features like backup, import & export have been removed in favor of a simpler usage model. Not suitable everyone, but fits the purpose we need it for.
Memorizes an MD5 hash of the crontab as it was last read. If on update the hashsums don't match the update is rejected.
The read & hash check operation is not atomic (even in Node.js's single-thread model). It should be safe enough for most scenarios, but there is no strong protection against concurrent writes - Latest write wins.
Fork and run node app.js. Open webbrowser on port 8000 by default.
Anything that has a crontab command should work.