Test for Ed25519 and Ed448. If both algorithms are not supported, skip
test. If only one algorithm is supported, run test, skip the
unsupported algorithm. If both are supported, run test normally.
Create new ns3. This will test Ed448 specifically, while now ns2 only
tests Ed25519. This moves some files from ns2/ to ns3/.
The $SYSTEMTESTTOP shell variable if often set to .. in various shell
scripts inside bin/tests/system/, but most of the time it is only
used one line later, while sourcing conf.sh. This hardly improves
code readability.
$SYSTEMTESTTOP is also used for the purpose of referencing
scripts/files living in bin/tests/system/, but given that the
variable is always set to a short, relative path, we can drop it and
replace all of its occurrences with the relative path without adversely
affecting code readability.
The eddsa test was not adapted to dynamic ports, so we had to run it in
sequence. This commit adds support for dynamic ports, and also makes
all the scripts shellcheck clean.
