Return with exit code when --ask is not accepted

[Jeidnx]

This change exits the program with code 1 when the user rejects changing to the new configuration. The motivation behind this change is to make it easier to wrap this program in scripts.

As i have written in the code, i wanted to propagate the error properly but with color_eyre this doesn't seem to be an option.

I was also a bit confused what drop(out_dir) was doing there and couldn't understand the comment, so i changed it to something more clear.

[Jeidnx]

I've made the requested change and also split the changes into two commits.

[viperML]

Can you apply the same src/home.rs and src/clean.rs? Then it should be ready

[Jeidnx]

Of course, done