Hadoop HADOOP 2.0.5-alpha Release Notes

These release notes include new developer and user-facing incompatibilities, features, and major improvements.

Changes since Hadoop 2.0.4-alpha

HADOOP-9407. commons-daemon 1.0.3 dependency has bad group id causing build issues

Committed to branch-2.0.5 Modified changes.txt in trunk, branch-2 and branch-2.0.5-alpha accordingly.