TEMP improve ssh handling

- set correct permissions for .ssh
- append instead of replacing existing authorized_keys

real fix should be to use ssh-copy-id instead
Fixed exception issues
Merge pull request #43 from paramite/master

yum-plugin-priorities
Merge pull request #39 from apevec/master

fix ssh key distribution
Merge branch 'master' of github.com:fedora-openstack/packstack