track and publish two new stats:

* netDb.failedPeers (how many peers didn't reply to a lookup in time)
* netDb.searchCount (how many searches we send out in a 3 hour period)
probabalistically include the leaseSet of the sender in the garlic sent
to a peer if the client requests it to be included (aka if they want
replies).  By default, this is enabled (disable by setting the I2CP
prop "shouldBundleReplyInfo=false").  Also, by default the probability is
30% (w00 h00, arbitrary values!), which can be overridden via the I2CP
prop "bundleReplyInfoProbability=80" (or =10, or =100, etc).  The tradeoff
here is quicker replies in exchange for bandwidth (the dbStore).
Yeah, it'd be nice if there were something keeping track of which leaseSet
each client sent to each peer so that it could explicitly include it only
if it were necessary, but for now that's probably overkill.