RFR: 8263636: Add --disableregistry option to jhsdb debugd [v3]

[Yasumasa Suenaga]

> `jhsdb debugd` will start RMI registry by default, but we want to prevent it due to port confliction in some cases. We can control it with `sun.jvm.hotspot.rmi.startRegistry` system property. However we have no way to set it excepting system property. jhsdb should provide the way to set it as a command line option.
> 
> This PR introduces `--disableregistry` to `jhsdb debugd`. Please review [CSR](https://bugs.openjdk.java.net/browse/JDK-8264021) too.

Yasumasa Suenaga has updated the pull request incrementally with one additional commit since the last revision:

  Fix help message for --connect

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/3233/files
  - new: https://git.openjdk.java.net/jdk/pull/3233/files/02d2b259..93c6f13e

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=3233&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=3233&range=01-02

  Stats: 2 lines in 1 file changed: 0 ins; 2 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/3233.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/3233/head:pull/3233

PR: https://git.openjdk.java.net/jdk/pull/3233