Error domain quarks need to be exported in the header files

Otherwise it is not possible to match the errors against them.
No PVs, VGs or LVs are not errors

There may simply be none in the system and should be reported that way.
Make parse_mdadm_vars function more usable

By taking separators as a parameters it can be used for key=value pairs as well as
'item : value' pairs separated with spaces, newlines, etc. Getting read of
leading and trailing whitespace also helps.
Add the md_detail function
Two elementary tests for UUID canonicalization and md_examine/detail