Add some macros

These were written by Will Vaughan.  Just checking them in.

I added several unit tests.  However these can't be run with pig 0.10 due to a bug in importing macros with PigUnit.  This will be fixed by pig 0.11.  For now they are disabled.  However they do pass with a patched pig 0.10.
Remove countByParallel.pig
Merge pull request #25 from evionkim/master

Fixed the bug in Enumerate
add WeightedSample udf and tests; add CountEach udf and tests
Release 0.0.8, bumping version
Update README, add settings.xml template
Merge branch 'master' of github.com:william-g-vaughan/datafu
change parameters based on matt's recommendations; change seed param in weighted sample
Merge pull request #26 from william-g-vaughan/master

Add UDFs for weighted sampling of a bag and counting elements of a bag
Add examples
Merge branch 'master' of github.com:matthayes/datafu
Test against pig 0.11
Readme update
Add .travis.yml
Merge branch 'master' of github.com:linkedin/datafu
Merge branch 'master' of github.com:linkedin/datafu
Turn off JvmMetrics log garbage
Remove appenders for root logger to reduce log spam
Update .travis.yml
Update .travis.yml