Transport: SSU1 removal part 2/n

See merge request !179

Console: Update rrd4j to version 3.9

See merge request !178

Without the ALLOW_UNASSIGNED flag, it will not decode to codepoints
newer than Unicode 3.2 (2002)

i2psnark: Add js drag-n-drop

See merge request !165

Susimail: DnD for attachments

See merge request !172

now that SSU1 is disabled.
SSU2 min packet size is 40 and does not support 0-byte hole punch

I2CP: Prevent loopback messages to same session (i2pd Github #2005)

See merge request !173

i2psnark: Bandwidth limiter improvements

See merge request !164

Possibly was changed back and forth due to iframe size issues?

reverts ccb0c279
which reverted eb72e4c9

i2ptunnel: Don't send html error messages on CONNECT

See merge request !175

Transport: SSU1 removal part 1/n

See merge request !174

Data: Store compressed KeysAndCert

See merge request !171

i2ptunnel: Prep for keepalive

See merge request !166

Susimail: Add markdown js for plain text content

See merge request !161

Console: Fix iframe size issues

See merge request !160

SSU2: Delay sending relay tag

See merge request !169

so we may begin to remove SSU1 code

Susimail: Speed up initial loading by 35x

See merge request !162

Console: News fetch improvements

See merge request !163

Tunnels: Peer selection adjustments

See merge request !167