Merge pull request #440 from pwendell/branch-0.6

Typo in Maven path (0.6 branch)
Use generation numbers for fetch failure tracking

Conflicts:
	core/src/main/scala/spark/scheduler/DAGScheduler.scala
Force generation increment after shuffle map stage
Extra debugging from hostLost()
Add tests of various node failure scenarios.
Remove dead code in test.
Clarify TODO.
Remove more dead code from test.
Call slaveLost on executor death for standalone clusters.
Remember ConnectionManagerId used to initiate SendingConnections.

This prevents ConnectionManager from getting confused if a machine
has multiple host names and the one getHostName() finds happens
not to be the one that was passed from, e.g., the BlockManagerMaster.
Fix compilation due to previous cherry-pick
Detect hard crashes of workers using a heartbeat mechanism.

Also fixes some issues in the rest of the code with detecting workers this way.
Properly deal with removed hosts in BlockManagerMaster
Increase worker timeouts
Change dependency to Akka repo to deal with a Maven dependency problem
(in resolving commons-httpclient 3.0.1)
Some bug and formatting fixes to FT
Tweak web UI so that people don't get confused about master URL format
Use a separate memory setting for standalone cluster daemons
Update tutorial to list Akka repository instead of Typesafe
Retrieve jars to a flat directory so * can be used for the classpath.

Conflicts:
	run