fix stupid bug in LARS, see #3467

When switching the enqueueing logic to use the actual time instead of
the current tick number (which had been the purpose of the whole
rewrite) I managed to make the same mistake I did half a year ago again:
enqueueing into the same slot that has just been processed needs to
subtract one round while enqueueing into the slot that is about to be
processed MUST NOT DO THIS.

There was another bug in there related to differences between tick
number and actual time and remaining ticks of the task. I hope that the
code is now clear and simple enough as to be actually correct. As usual,
all tests passing.
Merge pull request #1562 from akka/wip-LARS-2.1-∂π

fix stupid bug in LARS
Java (Eclipse) compatibility of extensions, see #3469

* Eclipse JDT showed compilation error
  "The method get(ActorSystem) is ambiguous for the type..."
  for extensions defined with ExtensionKey
Minor touchups and cleanups in ActorSelection
Turn of retry-limit for AkkaProtocolStressTest #3466

 This test drops messages, but dropping too much will make it fail. The reason is that this test expects at least a few of the final messages to arrive to prove that the Remoting does not get stuck in an irrecoverable state. The retry limit enabled case is covered by the SystemMessageDelivery tests. This is basically a revert to the original configuration.
Merge pull request #1564 from drewhk/wip-3466-retry-limit-off-apt-stress-drewhk

Turn of retry-limit for AkkaProtocolStressTest #3466
Merge pull request #1538 from akka/wip-3434-fix-dead-link-in-io-codec-√

 #3434 - Fixing dead link to Iteratees in io-codec.rst
Merge pull request #1563 from akka/wip-3469-ExtensionKey-patriknw

Java (Eclipse) compatibility of extensions, see #3469
add pipeToSelection support, see #3430

also add explanation to docs about what happens when Identify message
hits a non-existing path element
change line endings to CRLF for akka.bat
Replaced multi-line strings with \n and concatenation #3462

If multi-line strings are used, the encoding of the source file will determine the result. Since the same file generates *nix and Windows scripts, no encoding will be correct except if explicit \n markers are used.
Merge pull request #1567 from drewhk/wip-3462-akka-plugin-crlf-vs-lf-drewhk

Replaced multi-line strings with \n and concatenation #3462
Merge pull request #1566 from akka/wip-3430-pipeToSelection-∂π

add pipeToSelection support, see #3430
unhandled msg in cluster StressSpec
Removing the use of 'null' in LARS
Merge pull request #1565 from akka/wip-actor-selection-touchup-√

Minor touchups and cleanups in ActorSelection
Merge pull request #1569 from akka/wip-unhandled-msg-StressSpec-patriknw

unhandled msg in cluster StressSpec
fix yet another bug in LARS, see #3471

- the scheduler should round up the calculated slot instead of rounding
  down
- SchedulerSpec did not catch this because it added 5ms leeway (which is
  wrong and now removed)
- InboxActor exposed it by being really picky with early-firing timers;
  change that to be more robust
Merge pull request #1570 from akka/wip-the-great-un-nulling-√

Removing the use of 'null' in LARS
Fixing missing notFull-signal in BoundedBlockingQueue drainTo and clear