Release Notes - Apache Twill - 0.8.0

Improvements:
[TWILL-107] Support payloads for Discoverables
[TWILL-167] Add toString() to FileContextLocation
[TWILL-184] Allow user to disable the SecureStoreUpdater in Twill
[TWILL-188] LocationFactory should have options to accept permission for create

Bug fixes:
[TWILL-163] LocationFactory.getHomeLocation method returns home location of the user running the application instead of the user that owns the hdfs directories.
[TWILL-173] Application Master failed with BindException occasionally
[TWILL-175] Hadoop21YarnAppClient caches a YarnClient
[TWILL-177] ZKDiscoveryService should have a way to remove its connection watcher
[TWILL-182] ApplicationBundler will overwrite dependencies with identical names
[TWILL-190] Restart of a TwillRunnable does not wait for the runnable to stop