RFR: 8253470: Javadoc clean up in Filter and Headers [v3]

[Patrick Concannon]

> Hi,
> 
> Could someone please review my doc-only fix for JDK-8253470 - 'Javadoc clean up in Filter and Headers' ?
> 
> This fix is set of formatting changes intended to clean up the javadoc of the following classes :
> 
> `com.sun.net.httpserver.Filter`
> `com.sun.net.httpserver.Filter.Chain`
> `com.sun.net.httpserver.Headers`
> 
> This issue is a sub-task of [JDK-8252822](https://bugs.openjdk.java.net/browse/JDK-8252822)
> 
> Kind regards,
> Patrick

Patrick Concannon has updated the pull request with a new target base due to a merge or a rebase. The incremental
webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains two additional commits
since the last revision:

 - Merge remote-tracking branch 'origin/master' into JDK-8253470
 - 8253470: Javadoc clean up in Filter and Headers

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/429/files
  - new: https://git.openjdk.java.net/jdk/pull/429/files/bfff3c86..66d628fd

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=429&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=429&range=01-02

  Stats: 6798 lines in 1446 files changed: 1875 ins; 1003 del; 3920 mod
  Patch: https://git.openjdk.java.net/jdk/pull/429.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/429/head:pull/429

PR: https://git.openjdk.java.net/jdk/pull/429