RFR: JDK-8262899: TestRedirectLinks fails [v2]

[Jonathan Gibbons]

> Please review a trivial change to fix this test when run behind a firewall with a proxy set.
> 
> Previously, the test used `InetAddress.getLocalHost` which returns an IP address for the current host.  It runs a temporary local web server on that address, but since the address is typically not on the `nonProxyHosts` list, the attempted access to the web server goes to the proxy, and fails.
> 
> The fix is to explicitly use `127.0.0.1`, which should never go to a proxy, if one is set.

Jonathan Gibbons has updated the pull request incrementally with one additional commit since the last revision:

  Address review comments:
  * Use InetAddress.getLoopbackAddress
  * Suppress irrelevant doclint warnings
  * Check if testURL host is resolveable
  * Report duration if test connection fails
  
  (Duration is ~75 seconds on local machine.)

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/3137/files
  - new: https://git.openjdk.java.net/jdk/pull/3137/files/dd006db1..19d7168e

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=3137&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=3137&range=00-01

  Stats: 26 lines in 1 file changed: 20 ins; 0 del; 6 mod
  Patch: https://git.openjdk.java.net/jdk/pull/3137.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/3137/head:pull/3137

PR: https://git.openjdk.java.net/jdk/pull/3137