Merge pull request #560 from pwendell/logging. Closes #560.

[WIP] SPARK-1067: Default log4j initialization causes errors for those not using log4j

To fix this - we add a check when initializing log4j.

Author: Patrick Wendell <pwendell@gmail.com>

== Merge branch commits ==

commit ffdce513877f64b6eed6d36138c3e0003d392889
Author: Patrick Wendell <pwendell@gmail.com>
Date:   Fri Feb 7 15:22:29 2014 -0800

    Logging fix

(cherry picked from commit b6d40b782327188a25ded5b22790552121e5271f)
Signed-off-by: Reynold Xin <rxin@apache.org>
Merge pull request #562 from jyotiska/master. Closes #562.

Added example Python code for sort

I added an example Python code for sort. Right now, PySpark has limited examples for new people willing to use the project. This example code sorts integers stored in a file. I was able to sort 5 million, 10 million and 25 million integers with this code.

Author: jyotiska <jyotiska123@gmail.com>

== Merge branch commits ==

commit 8ad8faf6c8e02ae1cd68565d98524edf165f54df
Author: jyotiska <jyotiska123@gmail.com>
Date:   Sun Feb 9 11:00:41 2014 +0530

    Added comments in code on collect() method

commit 6f98f1e313f4472a7c2207d36c4f0fbcebc95a8c
Author: jyotiska <jyotiska123@gmail.com>
Date:   Sat Feb 8 13:12:37 2014 +0530

    Updated python example code sort.py

commit 945e39a5d68daa7e5bab0d96cbd35d7c4b04eafb
Author: jyotiska <jyotiska123@gmail.com>
Date:   Sat Feb 8 12:59:09 2014 +0530

    Added example python code for sort

(cherry picked from commit 2ef37c93664d74de6d7f6144834883a4a4ef79b7)
Signed-off-by: Reynold Xin <rxin@apache.org>