In the process, break out AMQP config into its own struct, one per service.
The AMQPConfig struct is included by composition in the config structs that need
it. If any given service lacks an AMQP config of its own, it gets a default
value from the top-level AMQP config struct, for deployability reasons.
Tightens the RPC code to take a specific AMQP config, not an over-broad
cmd.Config.
Shortens construction of specific RPC clients so they instatiate the generic
client connection themselves, simplifying per-service startup code.
Remove unused SetTimeout method on RPC clients.
This allows us to call the Google Safe Browsing calls through the VA.
If the RA config's boolean UseIsSafeDomain is true, the RA will make the RPC
call to the VA during its NewAuthorization.
If the VA config's GoogleSafeBrowsingConfig struct is not nil, the VA
will check the Google Safe Browsing API in
VA.IsSafeDomain. If the GoogleSafeBrowsingConfig struct is nil, it will
always return true.
In order to actually make requests, the VA's GoogleSafeBrowsingConfig
will need to have a directory on disk it can store the local GSB hashes
it will check first and a working Google API key for the GSB API.
Fixes#1058
Jacob Hoffman-Andrews
Jeff Hodges