Debian: Backport fixes from 0.9.30-4 package (ticket #2027)

and add buster files

* debian/NEWS: remove
* debian/README.Debian: update
* debian/compat: set compat level to 9.
* debian/control: added ${misc:Depends} to i2p & libjbigi-jni's Dep.
* debian/control: added bash-completion build dep
* debian/control: remove version on lsb-base dep
* debian/rules: fixed a typo (override_dh_dhlibdeps -> override_dh_shlibdeps).
* debian/rules: remove apps/susidns/src/lib/standard.jar symlink on clean.
* debian/i2p.postinst: Fixed a typo (missing ")" in /etc/default/i2p).

debian/README.Debian

@@ -1,3 +1,19 @@
+QUICK START:
+
+$ i2prouter start
+
+(do NOT use sudo or run it as root!)
+
+Then your web browser will start and show http://localhost:7657 (or you may run it manually).
+
+You can configure i2p (run on boot, memory limit, using apparmor) via debconf:
+
+# dpkg-configure -plow i2p
+
+See also: https://geti2p.net/en/download/debian
+
+-----
+
 There are a few changes in this package from upstream.
 
 - eepget and i2prouter are installed to /usr/bin.