RFR: JDK-8277795: ldap connection timeout not honoured under contention [v4]

[Rob McKenna]

> This fix attemps to resolve an issue where threads can stack up on each other while waiting to get a connection from the ldap pool to an unreachable server. It does this by having each thread start a countdown prior to holding the pools' lock. (which has been changed to a ReentrantLock) Once the lock has been grabbed, the timeout is adjusted to take the waiting time into account and the process of getting a connection from the pool or creating a new one commences.
> 
> Note: this fix also changes the meaning of the connection pools initSize somewhat. In a situation where we have a large initSize and a small timeout the first thread could actually exhaust the timeout before creating all of its initial connections. Instead this fix simply creates a single connection per pool-connection-request. It continues to do so for subsequent requests regardless of whether an existing unused connection is available in the pool until initSize is exhausted. As such it may require a CSR.

Rob McKenna 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 seven additional commits since the last revision:

 - Add method to guard long to int cast
 - Allow the test to pass on MacOSX
 - JDK-8277795: whitespace
 - Add test
 - JDK-8277795: formatting
 - JDK-8277795: whitespace cleanup
 - JDK-8277795: ldap connection timeout not honoured under contention

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/6568/files
  - new: https://git.openjdk.java.net/jdk/pull/6568/files/7c277622..6af94f37

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=6568&range=03
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=6568&range=02-03

  Stats: 73668 lines in 2120 files changed: 50786 ins; 12701 del; 10181 mod
  Patch: https://git.openjdk.java.net/jdk/pull/6568.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/6568/head:pull/6568

PR: https://git.openjdk.java.net/jdk/pull/6568