* Moved Scan Builder to Druids class and started on Scan Benchmark setup
* Need to form queries
* It runs.
* Remove todos
* Change number of benchmark iterations
* Changed benchmark params
* More param changes
* Made Jon's changes and removed TODOs
* Broke some long lines into two lines
* Decrease segment size for less memory usage
* Committing a param change to kick teamcity
* Prohibit assigning concurrent maps into Map-types variables and fields; Fix a race condition in CoordinatorRuleManager; improve logic in DirectDruidClient and ResourcePool
* Enforce that if compute(), computeIfAbsent(), computeIfPresent() or merge() is called on a ConcurrentHashMap, it's stored in a ConcurrentHashMap-typed variable, not ConcurrentMap; add comments explaining get()-before-computeIfAbsent() optimization; refactor Counters; fix a race condition in Intialization.java
* Remove unnecessary comment
* Checkstyle
* Fix getFromExtensions()
* Add a reference to the comment about guarded computeIfAbsent() optimization; IdentityHashMap optimization
* Fix UriCacheGeneratorTest
* Workaround issue with MaterializedViewQueryQueryToolChest
* Strengthen Appenderator's contract regarding concurrency
* fix issue with SingleLongInputCachingExpressionColumnValueSelector when sql compatible null handling enabled
* add test with doubles to show same behavior for floats/doubles that lack the optimization of longs
* simplify
* fix import
* blooming aggs
* partially address review
* fix docs
* minor test refactor after rebase
* use copied bloomkfilter
* add ByteBuffer methods to BloomKFilter to allow agg to use in place, simplify some things, more tests
* add methods to BloomKFilter to get number of set bits, use in comparator, fixes
* more docs
* fix
* fix style
* simplify bloomfilter bytebuffer merge, change methods to allow passing buffer offsets
* oof, more fixes
* more sane docs example
* fix it
* do the right thing in the right place
* formatting
* fix
* avoid conflict
* typo fixes, faster comparator, docs for comparator behavior
* unused imports
* use buffer comparator instead of deserializing
* striped readwrite lock for buffer agg, null handling comparator, other review changes
* style fixes
* style
* remove sync for now
* oops
* consistency
* inspect runtime shape of selector instead of selector plus, static comparator, add inner exception on serde exception
* CardinalityBufferAggregator inspect selectors instead of selectorPluses
* fix style
* refactor away from using ColumnSelectorPlus and ColumnSelectorStrategyFactory to instead use specialized aggregators for each supported column type, other review comments
* adjustment
* fix teamcity error?
* rename nil aggs to empty, change empty agg constructor signature, add comments
* use stringutils base64 stuff to be chill with master
* add aggregate combiner, comment
* * Add few methods about base64 into StringUtils
* Use `java.util.Base64` instead of others
* Add org.apache.commons.codec.binary.Base64 & com.google.common.io.BaseEncoding into druid-forbidden-apis
* Rename encodeBase64String & decodeBase64String
* Update druid-forbidden-apis
* Replacing Math.random() with ThreadLocalRandom.current().nextDouble()
* Added java.lang.Math#random() in forbidden-apis.txt
* Minor change in the message - druid-forbidden-apis.txt