use copy and unlink instead of rename. Might be universally the better option for all environments (i.e. NFS)

- added possibility to execute mkdirpath, file_put_contents and file_get_contents as unprivileged user, partly implements #5417

- fixed warning in chmod

- moved jailkit functions from bash files to system library

add optional arrays for service-name to function system->getinitcommand and also a parameter to check if the current service exists (mandatory if you use an array)

FS#3897 - backup - delete unused file (interval = none), fixed mail-backup delete, moved mail-function for failed mounts/umounts