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 #22 from njwhite/master

SetIntersect shouldn't throw NPEs when either of the input bags are empty
correct misspelling or retrieve in build.xml
Merge pull request #23 from talevy/patch-1

correct misspelling or retrieve in build.xml
Add inputSchema checking to SimpleEvalFunc so the schema is checked at pig compile time, instead of run time.
Fix the log message for type mismatches in SimpleEvalFunc.
Small fix to SimpleEvalFunc javadoc
Merge pull request #24 from rmelick/master

 Add inputSchema checking to SimpleEvalFunc so the schema is checked at pig compile time, instead of run time.
Update eclipse files
Merge branch 'master' of github.com:linkedin/datafu
Released 0.0.7, bumping version
Add notes on how to release
Fix the bug in Enumerate
Fixed the bug in Enumerate
Merge branch 'master' of github.com:evionkim/datafu
Change in BagTests
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