Add SetDifference UDF
Add HyperLogLogPlusPlus UDF
Clean up ivy.xml
Clean up test classpaths

Some JARs, like fastutil, are packaged in the datafu JAR under a different namespace.  For this reason they are not included in the pom.  To properly test datafu these JARs should not be in the namespace used for testing.  This wasn't the case.  So we couldn't be sure that the datafu JAR worked without the fastutil JAR be downloaded.  I've fixed this by having separate classpaths for building the JAR, building the tests, and running the tests.

Other changes:
* Updated NOTICE.
* Updated pom-template.
* TransposeTupleToBag doc fix.
Autojar commons-math and stream into datafu so not required as dependencies

This increases the JAR size about 400k to about 750k.
Fix eclipse .classpath

Needed to reference the libraries.properties file so versions are known.

[ci skip]
Merge pull request #73 from matthayes/master

Add SetDifference, HyperLogLogPlusPlus, and improve tests