config_eval(): sanity fixes.
rpigo_fatal() now returns OPTERR on getopts error.
config_eval() now has prefix/suffix options.
config_eval() can  now handle multiple files.
config_eval() now ignores blank lines.
storaged now loads its config file.
Fix typo causing storaged to always warn about the volume_format.
Use sudo -n instead of sudo in storaged.
Add blkid to sudo setup.
Better info message in storaged before mount.
More sudo => sudo -n fixes.