prevent /status from redirect, fixes #953

Backport update jetty curator

curator is more strict now

fix cardinality aggregator caching

update spymemcached library

for fixes mainly related to -
1) memory leaks on reconnects
2) better handling of network issues

fix smile exception on error + content-type

(0.6.x Backport) Multiple speed improvements revolving around topN with HLL

(Backport)

Change serializer / deserializer for HyperLogLog
* Changed DirectDruidClient's InputStream handling. Is now ~10% faster for data heavy queries, and has lower variance in execution speed.
* Changed HLL Collector's toByteStream() method to be better optimized for small values. Is notably faster for small result quantities which fall into the sparse HLL bucket codepath.
  * No change for dense HLL which just uses a direct bytestream of the underlying byte data.

TopNNumericResultBuilder semi-aggressive loop unrolling for metricVals

Benchmark for HLL for sparse packing (small HLL bucket population):
HyperLogLogSerdeBenchmarkTest.benchmarkToByteBuffer[0]: [measured 100000 out of 100100 rounds, threads: 1 (sequential)]
 round: 0.00 [+- 0.00], round.block: 0.00 [+- 0.00], round.gc: 0.00 [+- 0.00], GC.calls: 216, GC.time: 0.42, time.total: 15.96, time.warmup: 0.22, time.bench: 15.74
HyperLogLogSerdeBenchmarkTest.benchmarkToByteBuffer[1]: [measured 100000 out of 100100 rounds, threads: 1 (sequential)]
 round: 0.00 [+- 0.00], round.block: 0.00 [+- 0.00], round.gc: 0.00 [+- 0.00], GC.calls: 217, GC.time: 0.45, time.total: 13.87, time.warmup: 0.02, time.bench: 13.85
HyperLogLogSerdeBenchmarkTest.benchmarkToByteBuffer[2]: [measured 100000 out of 100100 rounds, threads: 1 (sequential)]
 round: 0.00 [+- 0.00], round.block: 0.00 [+- 0.00], round.gc: 0.00 [+- 0.00], GC.calls: 55, GC.time: 0.16, time.total: 4.13, time.warmup: 0.00, time.bench: 4.12
HyperLogLogSerdeBenchmarkTest.benchmarkToByteBuffer[3]: [measured 100000 out of 100100 rounds, threads: 1 (sequential)]
 round: 0.00 [+- 0.00], round.block: 0.00 [+- 0.00], round.gc: 0.00 [+- 0.00], GC.calls: 55, GC.time: 0.16, time.total: 4.30, time.warmup: 0.00, time.bench: 4.30
HyperLogLogSerdeBenchmarkTest.benchmarkToByteBuffer[4]: [measured 100000 out of 100100 rounds, threads: 1 (sequential)]
 round: 0.00 [+- 0.00], round.block: 0.00 [+- 0.00], round.gc: 0.00 [+- 0.00], GC.calls: 8, GC.time: 0.03, time.total: 1.10, time.warmup: 0.00, time.bench: 1.09
HyperLogLogSerdeBenchmarkTest.benchmarkToByteBuffer[5]: [measured 100000 out of 100100 rounds, threads: 1 (sequential)]
 round: 0.00 [+- 0.00], round.block: 0.00 [+- 0.00], round.gc: 0.00 [+- 0.00], GC.calls: 8, GC.time: 0.03, time.total: 0.72, time.warmup: 0.00, time.bench: 0.72
HyperLogLogSerdeBenchmarkTest.benchmarkToByteBuffer[6]: [measured 100000 out of 100100 rounds, threads: 1 (sequential)]
 round: 0.00 [+- 0.00], round.block: 0.00 [+- 0.00], round.gc: 0.00 [+- 0.00], GC.calls: 1, GC.time: 0.00, time.total: 0.60, time.warmup: 0.00, time.bench: 0.60
HyperLogLogSerdeBenchmarkTest.benchmarkToByteBuffer[7]: [measured 100000 out of 100100 rounds, threads: 1 (sequential)]
 round: 0.00 [+- 0.00], round.block: 0.00 [+- 0.00], round.gc: 0.00 [+- 0.00], GC.calls: 2, GC.time: 0.01, time.total: 0.26, time.warmup: 0.00, time.bench: 0.25

Updates to HyperLogLogCollector toByteBuffer() based on code review

Removed changes from DirectDruidClient from this branch and put it in another branch.

Changed HyperLogLogCollector to have protected getters and setters

Remove unused ByteOrder from HyperLogLogCollector

Copyright header on HyperLogLogSerdeBenchmarkTest

Now with less ass!

Reformat in TopNNumericResultsBuilder. No code change

Removed unused import in HyperLogLogCollector

Replace AppendableByteArrayInputStream in DirectDruidClient
* Replace with SequenceInputStream fueled by an enumeration of ChannelBufferInputStream which directly wrap the response context ChannelBuffer

Modify TopNQueryQueryToolChest to use Arrays instead of Lists

Modify TopNQueryQueryToolChest to use Arrays instead of Lists

Revert accidental changes to DirectDruidClient

They should be in another merge request:
https://github.com/metamx/druid/pull/893

Fixes from code review
* Extracting names from AggregatorFactory classes now done with TopNQueryQueryToolChest.extractFactoryName
* Renamed variable in TopNNumericResultBuilder

Conflicts:
	processing/src/main/java/io/druid/query/topn/TopNNumericResultBuilder.java
	processing/src/main/java/io/druid/query/topn/TopNQueryQueryToolChest.java

backport: optionally choose what worker to send tasks to

Conflicts:
	indexing-service/src/main/java/io/druid/indexing/overlord/http/OverlordResource.java
	services/src/main/java/io/druid/cli/CliOverlord.java

move IndexTask to use hashed partition; fixes #815

Conflicts:
	indexing-service/src/main/java/io/druid/indexing/common/task/IndexTask.java

Conflicts:
	server/src/main/java/io/druid/server/coordinator/helper/DruidCoordinatorRuleRunner.java

Backport filtered Aggregator fixes + enhancements