RFR: 8209137: Add ability to bind to specific local address to HTTP client

[Jaikiran Pai]

This change proposes to implement the enhancement noted in https://bugs.openjdk.java.net/browse/JDK-8209137.

The change introduces a new API to allow applications to build a `java.net.http.HTTPClient` configured with a specific local address that will be used while creating `Socket`(s) for connections.

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Commit messages:
 - Merge latest from master branch
 - add a note to the javadoc of the new API to explain that calling localAddress() is only for advanced usages
 - move the security checks to the HttpClient itself instead of the builder
 - first round of security manager checks
 - use IPSupport in test and don't rely on ipv4/ipv6 being available
 - use correct IPv6 "any address"
 - Refactor the test to use the HttpServerAdapters test infrastructure
 - increase the jtreg maxOutputSize for java/net/httpclient tests
 - Enhance HttpServerAdapters test infrastructure to allow returning client remote address from the (test) exchanges
 - print the stacktrace, to aid debugging, from Http2TestServer when server fails to start
 - ... and 4 more: https://git.openjdk.java.net/jdk/compare/aed3ea20...5ab5a61a

Changes: https://git.openjdk.java.net/jdk/pull/6690/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=6690&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8209137
  Stats: 427 lines in 8 files changed: 425 ins; 0 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk/pull/6690.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/6690/head:pull/6690

PR: https://git.openjdk.java.net/jdk/pull/6690