* Add some new expression functions and macros.
See misc/math-expr.md for the list of added functions, except for
"like", which previously existed but was not documented.
* Add easymock to datasketches tests.
* Add easymock to distinctcount tests.
* Add easymock to virtual-columns tests.
* Code review comments.
* Clean up code a bit.
* Add easymock to scan-query tests.
* Rework ExprMacros that have multiple impls.
* Improve test coverage.
* streaming version of select query
* use columns instead of dimensions and metrics;prepare for valueVector;remove granularity
* respect query limit within historical
* use constant
* fix thread name corrupted bug when using jetty qtp thread rather than processing thread while working with SpecificSegmentQueryRunner
* add some test for scan query
* add scan query document
* fix merge conflicts
* add compactedList resultFormat, this format is better for json ser/der
* respect query timeout
* respect query limit on broker
* use static consts and remove unused code
Roman Leventov
Gian Merlino
kaijianding