Read stderr from server for a short time before exiting

Previously we exited immediately without waiting to get any
error output.

This patch also adds the command line and directory to the
exception message on failure, in case the failure is due to
getting one of those wrong, for example.
Fix bug in release script due to typo.

* Fix collection typo
* Create shared command to setup 2.11 builds
* Alter snapshot detection to allow more flexible milestone versioning.
* Remove cusotm isSnapshot key for new sbt 0.13.2 isSnapshot key.
ServerApplication: yield before we check on the dumper thread
put backticks around `yield` in Thread.yield
Fix bug in release script due to typo.

* Fix collection typo
* Create shared command to setup 2.11 builds
* Alter snapshot detection to allow more flexible milestone versioning.
* Remove cusotm isSnapshot key for new sbt 0.13.2 isSnapshot key.
use custom scriptedParser instead of spaceDelimited parser

https://github.com/sbt/sbt/blob/v0.13.5/project/Sbt.scala#L179-L192
Also publish completions library for 2.11.
merge with master
Merge pull request #1350 from sbt/wip/fix-release-scripts

Fix bug in release script due to typo.
Improve test failure message for #1390.
Improve error message further.
Merge pull request #1383 from xuwei-k/scripted-parser

use custom scriptedParser instead of spaceDelimited parser
Merge pull request #1377 from havocp/wip/havocp-server-launch-errors

Read stderr from server for a short time before exiting
Adds support for Scala 2.12
One more fix to release script.

* Ensure completion is appropriately cross versioned
* The publish launcher task should not try to publish
  the useless root project.
Cleanup release settings not existing and credentials check/enforcement craziness.
Add special hook to diagnose travis failing test.
Wait 5 seconds instead of 2 seconds to read stderr from launched server
Flush output every time we write to it in StreamDumper

To try harder to get our errors displayed.
Don't delete the server config file if SBT_SERVER_SAVE_TEMPS ne null

This allows people to reproduce failures by running the command line
by hand.

Fixes #1394