Add a shuffle parameter to coalesce.

This is useful for when you want just 1 output file (part-00000) but
still up the upstream RDD to be computed in parallel.
Fix are/our typo.
Merge branch 'master' into shufflecoalesce

Conflicts:
	core/src/test/scala/spark/RDDSuite.scala
Use Boolean in the Java API, and != for assert.
Merge pull request #541 from stephenh/shufflecoalesce

Add a shuffle parameter to coalesce.