Global or per-user configuration variables

[tgharold]

All of these can be overridden at the user-specific or job-specific levels. The global configuration is read first, then the user-specific configuration, then the individual job might override values.

• email address for daily reports (optional, defaults to error email address)
• email address for errors
• email subject prefix/suffix (optional)
• LVM thin flag (see Can thin LVs be detected easily? #14)
• LVM VG name default (a lot of backups might be in same VG)
• USBBASE, USBPFX, USBSFX (see Parsing of a job file #3)
• Origin free space (eh, we don't care, no need to check origin space, see Write script to check file system free space/inodes #8)
• Destination free space % to warn / error (see Write script to check file system free space/inodes #8)
• Origin inodes / destination inodes, % used before warning / error
• LV extra space needed for snapshot (does not apply to thin?)

[tgharold]

No longer need email variables as user should use Cronic / Shush / Cronwrap instead.