RFR: 8365: Jolokia - Additional support for security mechanisms related to SSL / authentication, discovery restrictions

[Martin Skarsaune]

Note: The majority of the work in this PR is to make it work well with RMI connections. For Jolokia however, it should work out of the box as setting the env var will force https.

-------------

Commit messages:
 - JMC-8365: Make secure button updating null safe
 - JMC-8365: Actually reflect require secure connection back in wizard
 - JMC-8369: revert JmcJolokiaPlugin.java
 - JMC-8365: Remove premature change
 - JMC-8365: Fixed spots
 - JMC-8365: Add option to require secure connection and give hint in error connection if it fails

Changes: https://git.openjdk.org/jmc/pull/665/files
  Webrev: https://webrevs.openjdk.org/?repo=jmc&pr=665&range=00
  Issue: https://bugs.openjdk.org/browse/JMC-8365
  Stats: 67 lines in 12 files changed: 56 ins; 1 del; 10 mod
  Patch: https://git.openjdk.org/jmc/pull/665.diff
  Fetch: git fetch https://git.openjdk.org/jmc.git pull/665/head:pull/665

PR: https://git.openjdk.org/jmc/pull/665