Move argument checking to main client class

This makes the client::config class a bit more readable.

Signed-off-by: Gabriel Filion <gabster@lelutin.ca>
Lint manifests

Also chnage group from "root" to 0 for better portability.

Signed-off-by: Gabriel Filion <gabster@lelutin.ca>
Remove $server parameter and move remaining parameter-logic up to client

Using two parameters with almost the same name is really confusing. With
the proper value-checking in place, we can reuse $servers for both
configuration modes.

Bonus: repair condition for if clause in client::config. I had it
switched around when removing the "case" blocks.

Bonus 2: Give localhost as the default server. Specifying an empty list
of servers as a default value was not a good idea. With the new default
value, the worst case will be that a server will wrongly try to connect
to itself, but the module will configure things coherently still.

Signed-off-by: Gabriel Filion <gabster@lelutin.ca>
Split modes and reuse resources

client::config is easier to figure out this way, and we can reuse
resources to remove unwanted parts.

we're actually doing a better cleanup now.

Signed-off-by: Gabriel Filion <gabster@lelutin.ca>
default value for $servers should include port

usually apt-cacher-ng are on port 3142 so it should make sense to
provide a default that uses this port.

Signed-off-by: Gabriel Filion <gabster@lelutin.ca>