Fixes to magellan_user script.

- Some calls don't work reliably with the API so do
  them via the command line. IDK why.
- Also initial work pulling ENV variables from a config file.
Add mdstat script linux soft-RAID visibility.

- mdstat parses the output of /proc/mdstat and mdadm --detail /dev/mdX
  and returns several summary options: JSON by default, but two text
  modes '-d' for details on each physical disk and '-s' for summary
  information on each RAID device.