added thread ids to download folders

[wayubi]

self-explanatory, helps with organizing threads in filesystem because directories are sorted by id, not name.

optional, not a fix, but a feature, feel free to reject if not of value.

[Exceen]

thanks for your contributions!

I took a look at your changes and asked myself whether an argument called --append-names would make more sense. If you use no arguments at all, the script uses the IDs already anyway

[wayubi]

You're right, that's a better way of doing it, but then you lose the option of having only the name without the ID. Not sure if anyone uses it like that. For me, I like to keep the ID in there.

[Exceen]

You're right, that's a better way of doing it, but then you lose the option of having only the name without the ID. Not sure if anyone uses it like that. For me, I like to keep the ID in there.

I mean as an additional option, not replacing the existing one

[wayubi]

Ah, yes. That's a better idea, for when 4chan returns. Lol.