Add convenience parser/serialization wrappers for all configuration
variables that don't use the default config_parse_*() and
config_serialize_*() helpers yet. This is nothing but a dirty hack and
should be refactored later (e.g. by separating configuration variable
parsing and validation or by adding optional validation functions). It
makes it easier to switch to a more generic configuration parser,
though.
Signed-off-by: Lukas Fleischer <calcurse@cryptocrack.de>