Machine-parseable version number

## Feature Request

Please consider adding a tuple version of `libcloud.__version__`, so library consumers would be able to easily do comparisons and so on. Compare `sys.version` (string) and `sys.version_info` (named tuple).

Start by locating where libcloud.__version__ is defined and inspect how version information is exposed and tested. Compare the existing string value with Python's sys.version_info model, then verify that the added tuple form supports straightforward comparisons without changing the existing value.

Written by the indexing model from the issue text.