Various minor enhancements

Those commits come from #32. I've opened a separate PR as they should be ready to be reviewed

Most notable change lies in `NewestSemVerTag()`. Indeed, LibGit2Sharp doesn't enforce Tags (nor any References) to be returned in a sorted order.

As such, the call to `Reverse()` has been removed and the selection of the highest version to be returned has been delegated to `SemanticVersion`.

In order to ease the review of the commit diff, indentation fixes have been pushed in a separate commit.