Merge pull request #8 from nremond/utests

Fix unit test
Merge pull request #9 from nremond/deps

The 'datafu' dependency is unecessary
Tune up tests by storing QD and SQ comparison in files.
Handle repeated points without deletions (almost always).
Made ArrayDigest.Page static to avoid lost counts.
Final cleanups before new release.
Switch to version 2 to reflect change in API due
to making TDigest an abstract class.
[maven-release-plugin] prepare release t-digest-2.0
[maven-release-plugin] prepare for next development iteration
Fixed unexplained pdf corruption
Updated copyright
Add another layer of abstract class to make public interface clear.
[maven-release-plugin] prepare release t-digest-2.0.1
[maven-release-plugin] prepare for next development iteration
Reverted all Java7 features.  Happily only diamonds and try-with-resource in tests.
[maven-release-plugin] prepare release t-digest-2.0.2
[maven-release-plugin] prepare for next development iteration
Fix pageSize assumptions in Page.split().

Page.split() seems to assume 16 is half of the page size, and this makes
ArrayDigest fail to split pages when the page size is < 16 because of
out-of-bound exceptions.
Merge pull request #13 from jpountz/fix/array_page_size

Fix pageSize assumptions in Page.split().
Make TDigest instances able to summarize more than 2B values.

Centroid counts remain tracked as integers, but whenever counts of several
centroids need to be summed up, a long is used instead. This should allow
for summarizing datasets of at least several tens of billions of values.

Close #14