Adds the ability to use `$OS`  and `$ARCH`  variables in clients.config and plugins.config(updateURL.* only)

Fix for FileFilterDefinitionElement.  Issue #349

See merge request i2p-hackers/i2p.i2p!50

fix junit deprecations, issue #339

See merge request i2p-hackers/i2p.i2p!51

as discussed in #ls2 meeting
- Bob replies with Session Created even if skewed,
  so that Alice finds out what the skew is
- Alice handles Session Created timestamp and drops if skewed,
  bans Bob, and updates clock if NTP failed
- If Alice does reply with SessionConfirmed, Bob will send a
  destroy with a skew error code
- Don't change skew error code if netdb store failed
- Fix skew adjustment for RTT by Bob
- Call setLastBadSkew() in the right places
- Fix ntcp.invalidInboundSkew and ntcp.invalidOutboundSkew stats

Portion of gitlab MR !49

Change UDP-Sender queue from CoDel to CoDelPriority
No change to CoDel params

UDP msg priorities:
High priority: ack-only, session request/created/confirmed, relay request, hole punch, injected
Low priority: ping, destroy, peer test, relay intro/response

but without ooming
disabled in 2009 because of ooms

disabled since 2011

Allow chown to fail so files can be managed via docker configs and secrets

See merge request i2p-hackers/i2p.i2p!48

WIP - not hooked in, untested - target 1.8.0 / 0.9.54
Requires significant changes to TrackerClient
Adapted from mtn branch i2p.i2p.zzz.udpsnark (2014)
Ref: Proposal 160

Upgrade base image to latest version of Alpine

See merge request i2p-hackers/i2p.i2p!47

Turn jump button-links back into regular-looking hyperlinks when resolution indicates we are not on a mobile device

in the transports through PLRIJ via FNDF.publish()

otherwise relative to plugin name, as before