RFR: 8255853: Update all nroff manpages for JDK 16 release

[Magnus Ihse Bursie]

The man pages in src/$module/man/*.1 is generated from the (unfortunately still) closed markdown sources.

These needs to be updated for JDK 16. During this updating, a typo in the GPL header is also fixed (which caused Oracle's internal header verification tool to complain) -- a double space had been collapsed into a single space.

There is a certain possibility that man page content can still change for JDK 16. If that is the case, the export needs to be re-done. (In contrast to prior exports, we now have a standard way of doing this, so it's trivial to update.)

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Commit messages:
 - 8255853: Update all nroff manpages for JDK 16 release

Changes: https://git.openjdk.java.net/jdk/pull/1043/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=1043&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8255853
  Stats: 334 lines in 28 files changed: 202 ins; 25 del; 107 mod
  Patch: https://git.openjdk.java.net/jdk/pull/1043.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/1043/head:pull/1043

PR: https://git.openjdk.java.net/jdk/pull/1043