Improve Version Command

[DiscoStarslayer]

Based off a good catch from @mborgerson here: https://github.com/XboxDev/extract-xiso/issues/20#discussion_r250793780

The version command of extract-xiso (-v) is out of date as it is just hard-coded into the source.

Ideally this should be set by the current repo's tag/branch, or the current commit hash (and maybe dirty status?).

Having versions/commit hashes can aid with debugging user issues, especially as we now ship compiled binaries.