Allow to exit the program with <q> in addition to <esc>

[Alexey Dokuchaev]

In many *nix tools, quitting is often performed by hitting Q key, and it's rather annoying that only Esc is currently supported, especially that no other action is assigned to the Q key. Consider attached patch.

[Andrey Ugolnik]

Thank you, I apply this patch, check out development branch.