Truncate status when necessary

[atalii]

Would fix alire-project/alire#1329.

I tested only on Linux, and to be honest, I don't quite know what this patch does to platform support. I doubt there's any witchcraft capable of making this work on Windows; I've no idea what MacOS supports; and while I assume the ioctl's are the same on the various BSD's, I didn't check. @mosteo would you be able to clarify what platforms need to be tested?

[mosteo]

Hi @atalii, we would need this to be working, or at least non-breaking, for the three main OSes Alire runs on.

I know that GNATCOLL has a GNATCOLL.Terminal that supposedly is able to get the terminal width in all those OSes, but I have never tested it. I wouldn't also want to bring in such a large dependency just for that, but it may server as inspiration.

This is to answer your questions, I haven't actually looked in detail at the changes. I hope to do so without too much delay.

[atalii]

Thanks! I briefly looked at GNATCOLL.Terminal. The implementation for Windows is just a few lines of #ifdef'd C, and they use the same code for all the other platforms. Technically, it doesn't seem that supporting each platform is difficult or lengthy, but I don't have a MacOS or Windows device to test/develop on. I can try to set up virtual environments for each, but that might take a while.

Thanks again!

[atalii]

Sorry to get back to this so late! I just put everything under an #ifdef __linux__. I believe this code also works on MacOS, but I don't have the means to test it.

Re using Gnatcoll, I don't think it's preelaborate, so it can't be used here. Let me know if that's incorrect, though.

Hopefully this all looks good and works as I expect it to - thanks :)