Before this change, only passwords not containing shell metacharacters could be
used, and because the password was passed as a command-line argument, local
users could (in a very small window of time) record the password and (in an
indefinity window of time) record the length of the password.
We also use the opportunity to add a call to `exec` in the systemd start
script, so that no shell needs to hang around waiting for iodine to stop.
Systemd upstream provides targets for networking. This also includes a target network-online.target.
In this PR I remove / replace most occurrences since some of them were even wrong and could delay startup.
- services.iodined moved to services.iodine
- configuration file backwards compatable
- old iodine server configuration moved to services.iodine.server
- attribute set services.iodine.clients added to specify any number
of iodine clients
- example:
iodine.clients.home = { server = "iodinesubdomain.yourserver.com"; ... };
- client services names iodine-name where name would be home
