Exposed Feat, Features and most importantly Cmd fields

[DeadLockStarve]

Not exposing them prevents users from reading supported server features and sending custom server commands (Which are a possibility)
Please review as you wish as long as it respects the purpose of the commit, or at least motivate the rejection

[Jonher937]

Looks good to me, the only comment I have is that maybe the function signature of Feat() does not need to change? But since it wasn't public before, it does not matter much.

I guess there's a upside of returning the features to the Feat() caller so it can easily check for contents, but could just as well just check the len(c.Features) ?

Thanks for this PR; I came here as I was looking to expose Cmd myself