Added debug logging and extended start/stop timeouts as 20s seems too low.
Added CDDL license header and notice.
Added a short paragraph to the manpage explaining how stmf-ha
integrates with a cluster resource manager.
Documented all functions.
Removed import-lu usage. Instead, we just re-recreate the LU. This allows us to support LU renaming.
Changed command selection logic from if-elif sequence into a switch.
Small formatting fixes to fit into 80 columns.
Reworked command execution and logging into a single function and implemented
a dummy mode (no changes done, only shows commands that would have been
executed).

Changed logging to go to stderr.

Implemented persistent storage of LU GUID and LUN into a user-property in the
zvol to allow for zvol renaming. The initial GUID is still generated from an
MD5 of the initial zvol name.

Implemented parallel execution of delete-lu, delete-target and create-lu to
speed up import/export of pools with many zvols.
Removed the ':lun' naming scheme. Instead we let COMSTAR auto-determine the LUN
which we then persist using a ZFS user-property.