vagrant deploy: various bug fixes.
- Change Hadoop download site to archive.apache.org for better locality
- fix hostname issue in /etc/hosts that makes HDFS NN binds to 127.0.0.1
and other cannot connect

Signed-off-by: rootfs <hchen@redhat.com>
Merge pull request #509 from rootfs/fix-hdfs2

vagrant deploy: various bug fixes.