### FEATURE REQUEST

Currently, when a bitcoin node is set up with a connection to both TOR and normal IPv4/6 internet, the 8 outbound-only connection slots, almost always get filled with nodes connecting over IP.
Adding a config option, which would try to ballance these connections based on what kind of network they go through, would be benefficial in many ways:

1. It would add edges between bitcoin network on TOR and normal internet, reducing delays, and the risks associated with an attacker isolating a part of TOR-bitcoin-network from the rest of the world
(Or an ISP/government man-in-the-middling all the normal IP connections)

2. It would help hide/annonymise normal user's transactions from his/her ISP, by mixing them with TOR-outbound ones

3. It would reduce the stress on normal general purpose TOR exit nodes, as users would more likely/reliably connect to TOR-IPv4/6 bitcoin nodes instead of exiting into normal internet first, and then connecting to default IPv4/6-only bitcoin nodes

I understand it is possible to create such bridges already, by forcing connections to TOR-only nodes, or by just running a node with lots of inbound slots, but I think the proposed option, would greatly increase the number of such relays, and remove the need for user to maintain a TOR-node whitelist, by handing this work off to normal bitcoind connection finding algorithm.

This could be implemented as a minimum number of connections for each network, or just a simple evening boolean switch. (Which could be enabled by default for bitcoind installs with TOR connectivity)

In the future, if bitcoin was to support a new network type (for example cjdns/I2P/GNUnet), this option would help establish a presence on the new network faster

bitcoind: 0.15
const std::chrono::seconds seeds_wait_time = (addrman.size() >= DNSSEEDS_DELAY_PEER_THRESHOLD ? DNSSEEDS_DELAY_MANY_PEERS : DNSSEEDS_DELAY_FEW_PEERS);
    for (const std::string& seed : seeds) {
        if (seeds_right_now == 0) {
            seeds_right_now += DNSSEEDS_TO_QUERY_AT_ONCE;
            if (addrman.size() > 0) {
                LogPrintf("Waiting %d seconds before querying DNS seeds.\n", seeds_wait_time.count());
                std::chrono::seconds to_wait = seeds_wait_time;
                while (to_wait.count() > 0) {
                    
                    
                    
                    std::chrono::seconds w = std::min(DNSSEEDS_DELAY_FEW_PEERS, to_wait);
                    if (!interruptNet.sleep_for(w)) return;
                    to_wait -= w;
                    int nRelevant = 0;
                    {
                        LOCK(cs_vNodes);
                        for (const CNode* pnode : vNodes) {
                            if (pnode->fSuccessfullyConnected && pnode->IsOutboundOrBlockRelayConn()) ++nRelevant;
                        }
                    }
                    if (nRelevant >= 2) {