Bump version to 0.13.1
Avoid filling config file with default values

Fixes grnet/kamaki#85
Merge branch 'hotfix-0.13.1'
Update Changelog and version files for v0.13.1
Add ca-certificates to the debian dependencies
Merge branch 'master' into debian-precise
Bump version to 0.13.1-1~precise

Signed-off-by: Nikos Skalkotos <skalkoto@grnet.gr>