Needed for SSU2 handshakes

Caused SusiDNS and addressbook to be in a different context
addressbook config would be stored in base dir
and subscriptions would not load because it couldn't find i2ptunnel

Was never used; prep for actual usage
Move from router to core
Add Set constructors that are more efficient
Add addUnique() method
Allow size of set passed in constructors
Prepare for extension
javadocs

Validate and process hole punch payload
Send session request immediately after receiving hole punch
Remove some unused code
Log tweaks

Fix conn ids on hole punch
Fix min size on relay response

Enable relay
Set session created token to 0 as per spec
Log tweaks

Fix sending charlie's address in relay response
Fix sending session request after introduction
Send 0-length endpoint in relay response on failure
Log tweaks

Fixes after testnet testing:
Fix NPE in OES2 constructor
Fix relay request signature
Fix relay response signature verification bugs
Fix unhandled state OB_STATE_INTRODUCED
Refactor state handling to switch
Remove dup copy in SSU2Util.sign()
Log tweaks

Reject SSU1/SSU2 relay request mismatch as Bob

Don't send SSU1 relay request to SSU2-connected introducers
and vice versa
Log tweaks

as it is received in-session only
Log tweaks all over

to make it easier to debug SSU2 relay

prevent dup SSU2 introducers take 2

so rest of payload can be processed
Improve debug output on errors

This should actually fix the HMAC NPE

Fix OES2 initial state when pending intro
Handle relay response as Alice
Check relay request and relay response sigs as Bob
Remove unused method OES2.reset()
Fix javadoc for one OES state

Alice side:
check for valid v2 introducers,
fetch Bob RIs if not found,
connect if not connected,
then send relay request

Reduce SSU 1/2 max test time as Bob

Change failed transports from a Set to a List for efficiency
Check fail count before getting bids
Don't remove from netdb after a failure
Other minor tweaks

per spec, Alice hash not included in msg 1/2 sig
Add sig checks of msgs 1/3 at Bob
Fix checking of 'B' cap in peer selection

prevent dup SSU2 introducers

Put source address of msg 6 into address block for msg 7
Use msg 7 address block for received address

Add SSU2 parameter support to UDPAddress
Count SSU2 introducers in UDPAddress
Fix reuse of SSU2 introducers
Don't immediately remove introducer for idle time

Fix saving relay tag as Bob
Select introducers by newest connection instead of random
Ping introducers more often
Check and set ping time when pinging introducers
Remove unused nextCipherKey
Debug: Prefer selecting SSU2 introducers
Log tweaks

Possible fix for HMAC NPE

Publish SSU2 introducers

Decrypt and handle hole punch as alice

Put alice hash in relay intro as Bob
Fix relay intro/response generation and signing
Add token to relay response as Charlie
Store relay nonce as Bob
Handle relay response as Bob and forward to Alice
Stub out handling relay response as Alice