add s3 scheme as input stream
Add a log message for when fetching input fails.
Make the job coordinator a system process.

The reason the job coordinator was not a system process before was that
it's terminate would have been called when its parent (the http request
handler) finished.  This is not an erlang bug, the behaviour is explained
in this mail thread:
http://erlang.org/pipermail/erlang-questions/2005-January/013943.html
and in this stack overflow answer:
http://stackoverflow.com/a/7753788/830681

The solution is linking the http handler from the newly created child.
Add folsom as a dependency.
Simplify the implementation of two functions.
Start folsom on the slave nodes.
Add folsomite for exporting profiles.

Folsomite needs a remote graphite server.  It will be disabled by
default.
Add profiling to some functions in disco and ddfs.
Merge pull request #435 from pooya/shayan/folsomite

Shayan/folsomite
Replace disco ball image with the new disco logo.
Merge pull request #436 from pooya/kircic/develop

Replace disco ball image with the new disco logo.
Update AUTHORS
Add a separate metric for ddfs_web and disco_web.
Merge pull request #437 from pooya/shayan/web_histogram

Add a separate metric for ddfs_web and disco_web.
Merge pull request #394 from pooya/shayan/scheduler

Shayan/scheduler
Set the job variable before running tests.

If a test is interrupted, it is checked to see if they have a 'job'
associated with them and if so the job is purged.  However if a test
does something like:
  self.job = Job().wait()
the interruption will occur while it is waiting for the results and
the self.job is not set at this time, so it will not be purged.
Handle the kill_worker message in job_coordinator.
Merge pull request #438 from pooya/shayan/fix_job_interrupt

Shayan/fix job interrupt
Add a note about Disco installation.

This should resolve issue #440.
Do not fsync files after flushing them.

Fsync is only necessary when we are concerned about losing data when system
crashes and it is not a concern for the output of disk sort.