Saltext.proxmox

Removed

- removed superfluous code from `_get_properties()` and its callees (8)
- removed dead code from repository (20)
- removed OpenVZ code paths (27)

Changed

- Replaced IPy dependency with built-in module ipaddress (22)

Fixed

- fixed location parameter for `avail_images()` (25)

Added

- Initial version of Proxmox Cloud Modules Extension for Salt. This release
tracks the functionality in the core Salt code base as of version 3006.0.