Add documentation for image url
Support both v1 & v2 glance API

Fix #168

Endpoint /images exists on both v1 and v2 API
The attribute 'visibility' is used to detect
if the call has been made on v1 or v2

In case of v2 we have all the needed information,
but in case of v1 we don't and we have to call
/images/detail to get full details
Disbale sync only if sync method needs SSH
Avoid all ssh actions during vagrant up when ssh_disabled
i18n for ssh_disabled
Merge pull request #181 from ggiamarchi/issue#168

Issue #168 Support both v1 & v2 glance API
Merge pull request #182 from ggiamarchi/fix_ssh_disabled

Fix ssh_disabled
Refactor endpoint version resolution
Externalize catalog reader in a separated module
Support OpenStack regions

Fix #128
Documentation for regions
Resolve glance endpoint wathever the version