add -O/--overwrite

[nekopsykose]

i prefer this over echoing stuff to stdin like suggested in #174

up to you though, i don't mind if it's rejected :)

[ammen99]

Many package managers provide -y, maybe that would be better?

[nekopsykose]

that sounds good to me too. no preference here

[ammen99]

I'd say then make it a -y, let's keep to the conventions ;)

[nekopsykose]

at the time i wrote that in the middle of the night i forgot what letters of the alphabet were still available... :D

[ammen99]

Thanks!