mod_cron: Initial commit of periodic task runner A number of modules now have periodic tasks that need to run, e.g. for cleaning out old messages or files. This has highlighted a need for coordinating and optimizing scheduling of such tasks.

local xpcall = xpcall;

if select(2, xpcall(function (x) return x end, function () end,  "test")) ~= "test" then
	xpcall = require"util.compat".xpcall;
end

return {
	xpcall = xpcall;
};