Add boolean property to differentiate SSE
Report `SSE` on formatted version
Show "Enterprise" instead of "SSE"

Fixes saltstack/backlog#33
Version names only contain major and minor parts of the version
Regular `__version__` attribute must not include codename.

* Add `noc` and `sha` as `repr` attributes.
Stop hard coding the version name.

Fixes saltstack/backlog/issues#11
Switch `???` for `n/a`
Support a minor bugfix attribute in the version string
Add another example for version comparison
Add another version example to the tests
Add another which only changes the noc