Implement parsing of the new SigLevel directive

Add code to conf.c that parses the new SigLevel directive. An
overwhelming number of options are presented, but most users will still
be fine with the Never/Optional/Required trio. More advanced users can
combine these or any of the other options on a 'SigLevel = ' line, which
is parsed in a left-to-right fashion and flags turned on and off
accordingly. For example, all three of these will net the same config:

    SigLevel = Required PackageOptional
    SigLevel = Optional DatabaseRequired
    SigLevel = DatabaseRequired PackageOptional

Additionally, database-specific lines assume you wish to start with any
global default that has been set. For example, if any of the above lines
were in the [options] section, something such as:

    SigLevel = PackageRequired PackageAllowMarginal

Would continue to enforce required database signatures.

Inspiration-by: Kerrick Staley <mail@kerrickstaley.com>
Signed-off-by: Dan McGee <dan@archlinux.org>

0 files changed, 0 insertions, 0 deletions