SPARK-1941: Update streamlib to 2.7.0 and use HyperLogLogPlus instead of HyperLogLog.

I also corrected some errors made in the previous HLL count approximate API, including relativeSD wasn't really a measure for error (and we used it to test error bounds in test results).

Author: Reynold Xin <rxin@apache.org>

Closes #897 from rxin/hll and squashes the following commits:

4d83f41 [Reynold Xin] New error bound and non-randomness.
f154ea0 [Reynold Xin] Added a comment on the value bound for testing.
e367527 [Reynold Xin] One more round of code review.
41e649a [Reynold Xin] Update final mima list.
9e320c8 [Reynold Xin] Incorporate code review feedback.
e110d70 [Reynold Xin] Merge branch 'master' into hll
354deb8 [Reynold Xin] Added comment on the Mima exclude rules.
acaa524 [Reynold Xin] Added the right exclude rules in MimaExcludes.
6555bfe [Reynold Xin] Added a default method and re-arranged MimaExcludes.
1db1522 [Reynold Xin] Excluded util.SerializableHyperLogLog from MIMA check.
9221b27 [Reynold Xin] Merge branch 'master' into hll
88cfe77 [Reynold Xin] Updated documentation and restored the old incorrect API to maintain API compatibility.
1294be6 [Reynold Xin] Updated HLL+.
e7786cb [Reynold Xin] Merge branch 'master' into hll
c0ef0c2 [Reynold Xin] SPARK-1941: Update streamlib to 2.7.0 and use HyperLogLogPlus instead of HyperLogLog.

1 files changed, 2 insertions, 2 deletions

diff --git a/pom.xml b/pom.xml
index 0a5ca9e72a..fcd6f66b44 100644
--- a/pom.xml
+++ b/pom.xml
@@ -300,9 +300,9 @@
       <dependency>
         <groupId>com.clearspring.analytics</groupId>
         <artifactId>stream</artifactId>
-        <version>2.5.1</version>
+        <version>2.7.0</version>
         <exclusions>
-          <!-- Only HyperLogLog is used, which doesn't depend on fastutil -->
+          <!-- Only HyperLogLogPlus is used, which doesn't depend on fastutil -->
           <exclusion>
             <groupId>it.unimi.dsi</groupId>
             <artifactId>fastutil</artifactId>