Release 0.1.0

- drop default distribution root element support
- switch Ubuntu element to installing Saucy
- fix image creation when /etc/selinux/config doesn’t exist
- fix openssl/python issue in Fedora (bug 1254879)
- add mapping for tgt to RHEL element (bug 1252975)
- add --image-size option which allows to set the image size for the created image
- various docs and comments fixes