Implement string hash code in C.
Add function cogroup().
Fix the review comments.
Refine code and add description.
Use extendible accumulators aggregate the cogroup values.
Merge remote-tracking branch 'upstream/master' into hlin09
Minor fix.
Adding the script to install software on the Cloudera Quick Start VM.
Add keyBy() to the RDD class.
[SPARKR-144] Implement saveAsTextFile() in the RDD class.
Merge pull request #117 from sun-rui/keyBy

Add keyBy() to the RDD class.
Merge pull request #116 from dputler/master

Adding the script to install software on the Cloudera Quick Start VM to go along with the wiki entry.
fix reviews
Merge pull request #114 from hlin09/hlin09

Add function cogroup().
Fix build on Windows.
Merge pull request #113 from sun-rui/stringHashCodeInC

Implement string hash code in C.
[SPARKR-146] Support read/save object files in SparkR.
Add @seealso in comments and extract some common code into a function.
Merge pull request #120 from sun-rui/objectFile

[SPARKR-146] Support read/save object files in SparkR.
Sort lists before comparing in unit tests
Since Spark doesn't guarantee that shuffle results will always
be in the same order, we need to sort the results before comparing
for deterministic behavior