o change the parsing to get a key from the rule and sort it
into our list of known keys instead of expecting a special order
o the key to match a sysfs file must be prependend by 'SYSFS_' now
to match with the new parsing.
(The config must be changed, but it's a bit more descriptive too.)
o put names of fields in define's, like the name of the methods
o update all tests and the man page
