Updating reception stats before consuming. Can create trouble if there is any exception during consumption (less likely,) but this frees up splits that threads can connect to instead of idling around.

 - Fixed several bugs. (Copy-paste is the bane of coding :|)

 - Moved ShuffleTrackerStrategy to a separate file.

 - Why ShuffleClient and ShuffleServerThread are crashing is still unknown.

Bug fix: tracker (running in Spark master) wasn't initializing Shuffle object and was using inconsistent config values.

Conflicts:
	conf/java-opts

Tracker framework is in place that supports pluggable tracker strategy. There are several bugs along with performance problems.

 - For larger data shuffle ShuffleServerThread gets "Broken Pipe" and ShuffleClient gets "Connection Reset"
 - There is a bug in the accounting counters of BalanceConnectionsShuffleTrackerStrategy. Some of them go below zero while decrementing which is not supposed to happen.

CustomBlockedLocalFileShuffle has been added. This is essentially ManualBlockedLocalFileShuffle with our servers.

There will be a new CustomBlockedLocalFileShuffle where 'Custom' will mean ManualBlockedLocalFileShuffle with custom server instead of jetty.

We were serializing one (the wrong) thing, trying to deserialize another (the right thing).

Added an in-memory implementation of CustomParalleLFS. There is a serialization/deserialization bug in the implementation.

Fixed an indexing bug in HttpBlockedLocalFileShuffle. It still doesn't work on EC2 with >5 nodes cluster.

HttpBlockedLocalFileShuffle has also been converted to have per-reducer consumption thread. Works in local mesos, but NOT on EC2 :|

Upside: No synchronized blocking on "combiners" variable. 3x faster :)
Downside: Inefficient implementation. Requiring too much temporary data. Approx. 2x increase in memory requirement :( Should be fixed at some point.

 - Fixed config param loading bug in CustomParallelLFS

Conflicts:
	conf/java-opts
	src/scala/spark/BasicLocalFileShuffle.scala

Conflicts:
	conf/java-opts
	src/scala/spark/BlockedLocalFileShuffle.scala
	src/scala/spark/CustomBlockedLocalFileShuffle.scala
	src/scala/spark/HttpBlockedLocalFileShuffle.scala

Renamed BlockedLocalFileShuffle to HttpBlockedLocalFileShuffle for merging with the mos-shuffle branch.

 - Clients now request for byte ranges to the server using an INDEX file.

 - Config option related to pipelining has been removed.
 - Summary: Basic -> Pipelining / Parallel -> NO pipelining