RFR: JDK-8259727: Remove redundant "target" arguments to methods in Links

[Jonathan Gibbons]

Please remove a simple change to eliminate a now-unused parameter from various methods on `Links`, to set the `target` attribute of a link.

In times past, when frames were used to display pages, the `target` attribute was used to specify the target frame to use when clicking the link.

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Commit messages:
 - JDK-8259727: Remove redundant "target" arguments to methods in Links

Changes: https://git.openjdk.java.net/jdk/pull/2068/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=2068&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8259727
  Stats: 65 lines in 6 files changed: 0 ins; 28 del; 37 mod
  Patch: https://git.openjdk.java.net/jdk/pull/2068.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/2068/head:pull/2068

PR: https://git.openjdk.java.net/jdk/pull/2068