Ubiquiti removed keytool (and java) from recent releases of Unifi OS. This moves from keytool to openssl's native pkcs12.
Tested on Unifi Dream Machine which runs Unifi OS and a built-in Unifi controller.
Also added backup of existing files prior to change in case anything goes wrong, and update system configuration with compatible ciphers.
message:
SC2034: $VARNAME appears unused. Verify it or export it.
most of these are related to the style:
we generate global vars, which are used in other functions.
the var "lexical_url" was really unused (left it as comment)
the travis-check now does not need anymore special flags.
Signed-off-by: Bastian Bittorf <bb@npl.de>