Add join() to the RDD class.
Update documentation for join().
Adds countByValue().
Adds function countByKey().
Minor fix.
Adds function numPartitions().
Merge pull request #106 from hlin09/hlin09

Add function countByValue() and countByKey().
Fix slow take(): deserialize only up to necessary # of elements.
Rename the filter function to filterRDD to follow the API consistency. Filter() is also kept.
Min() upper-bound size with actual size.
Merge pull request #109 from hlin09/hlin09

[SPARKR-15] Rename the filter function to filterRDD to follow the API consistency.
Merge pull request #107 from shivaram/master

[SPARKR-136] Use SPARK_LOCAL_DIRS to create tmp files
Apply size-capping on logical representation instead of physical.

- This supercedes the previous commit, which is a wrong fix.
- Also, modify take() test slightly to cover all cases.
Fix: only optimize for unserialized dataset case.
Merge pull request #108 from concretevitamin/take-optimize

[SPARKR-139] Fix slow take(): deserialize only up to necessary # of elements.
Pre-allocate list with fixed length. Add test case for join() using string key.
Merge pull request #105 from sun-rui/join

Add join() to the RDD class.
Adds function foreach() and foreachPartition().
add Rd file for foreach and foreachPartition.
Add leftOuterJoin() and rightOuterJoin() to the RDD class.