Add a --local-only option to use only local cheats

[xgaia]

Hello !

I use this very useful tool most of the time with my own cheats.

This PR add an option to only load cheats in ~/.cheats.

What do you think about it?

[v1k1ngfr]

Hello @xgaia,

We have no feedback about this kind of usage, but maybe it could be useful for someone else.

Thanks

[Guilhem7]

Hey, thank you for the pull request !! We think that if someone wants to use personal cheats, it can directly changes them in the directory used by arsenal (changes/delete)