RFR: 8278067: Make HttpURLConnection default keep alive timeout configurable [v3]

[Michael McMahon]

> Hi,
> 
> Could I get the following patch reviewed please? (A CSR is also required which I will submit when the docs are agreed)
> 
> It adds a pair of new system properties to make the keep alive timer in java.net.HttpURLConnection configurable.
> The proposed property names are:
> 
> "http.keepAlive.time.server" and "http.keepAlive.time.proxy"
> 
> Thanks,
> Michael

Michael McMahon 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 12 additional commits since the last revision:

 - Merge branch 'master' into keepalive
 - update after Daniel's first review
 - Merge branch 'master' into keepalive
 - added docs
 - reverted change to LIFETIME constant. Were not necessary
 - updates
 - Merge branch 'master' into keepalive
 - Merge branch 'master' into keepalive
 - Merge branch 'master' into keepalive
 - Merge branch 'master' into keepalive
 - ... and 2 more: https://git.openjdk.java.net/jdk/compare/7e38b27f...b0b7673c

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/7349/files
  - new: https://git.openjdk.java.net/jdk/pull/7349/files/edcbb13f..b0b7673c

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=7349&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=7349&range=01-02

  Stats: 3129 lines in 84 files changed: 2334 ins; 392 del; 403 mod
  Patch: https://git.openjdk.java.net/jdk/pull/7349.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/7349/head:pull/7349

PR: https://git.openjdk.java.net/jdk/pull/7349