Eepsite: pull new and updated help translations

Replace possibly more-translated, but very very old (not from transifex) pages

refresh patches
update release docs

https://bugs.launchpad.net/ubuntu/+source/i2p/+bug/1784023

Ant version 1.9.8 or higher now required
Drop support for Xenial package build
Fix up BOB build configuration
Fix i2psnark standalone build

Patch adapted from Gilles Filippini
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=960589

Bundle 2.0 API only; remove 1.1 API
Convert DoH, NDT, and i2pcontrol to the 2.x API
Fix i2pcontrol handling of number values and serialization for 2.x API
Remove xenial dependency on libjson-simple-java, it has only 1.1
Set min and max version constraint on libjson-simple-java for bionic+
Based on patch from Gilles Filippini
ref: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=901827
This does not support 3.x but the patch for that will be smaller.

Add xenial patch to ant test target

Add ant target to validate patches

not needed for rrd4j with our patch

does nothing with Jetty 9.4 (ticket #2599)

require Jetty 9.4 or higher

Debian: Change debian files from stretch (Jetty 9.2, Tomcat 8, Java 8) to buster (Jetty 9.4, Tomcat 9, Java 11)
Add debian-alt/stretch files
Update debian-alt/precise, trusty, xenial, bionic, disco to include
 the changes from buster, not stretch
Remove debian-alt/buster, unstable files
Doc updates

Add links to Arabic, Hungarian, Indonesian
Fix link to Italian

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=925515

Allow any JRE or JDK to work