make lifecycle hooks work when using Stash, see #3199

Unfortunately the need to call super.postStop() and friends mandates
that Stash (and FSM had the same problem) extends Actor instead of just
declaring it as a self type. We cannot always win.
Fixed wrongly configured retry-gate to avoid test-interference and reduce logs
Fixed all occurences of "retry-latch"
 #3215 - fixing race in JavaTestkitSpec
Upgrade to Netty 3.6.5.Final, see #3218
Merge pull request #1326 from akka/wip-3215-fix-raec-in-JavaTestkitSpec—√

 #3215 - fixing race in JavaTestkitSpec
 #3198 - Making CoronerSpec taggedAs TimingTest
Merge pull request #1320 from drewhk/wip-3156-remotingspec-test-interference-drewhk

Fixed wrongly configured retry-gate to avoid test-interference
Merge pull request #1327 from akka/wip-3218-netty-3.6.5-patriknw

Upgrade to Netty 3.6.5.Final, see #3218
Merge pull request #1325 from akka/wip-3198-tag-coronerspec-as-timing-sensitive-√

 #3198 - Making CoronerSpec taggedAs TimingTest
Merge pull request #1317 from akka/wip-3199-ActWithStash-∂π

make lifecycle hooks work when using Stash, see #3199
Make karaf osgi-sample extract to target directory. See #3216
Merge pull request #1329 from akka/wip-3216-failed-akka-sample-osgi-ban

Make karaf osgi-sample extract to target directory #3216
Tone down error logging of DeathPactExceptions via dedicated SupervisorStrategy
Fix `Connectable channel failed to connect` assertion error on OS/X
Some cleanup