Acceleration does not work in interactive mode

Interactive mode does not honor acceleration given on command line (and no way to turn it on either).

```
klick -P -i 120-175/1
```

Just stays on 120 BPM.

Could acceleration be added to interactive mode? 

Alternatively, if this proves hard, is there a way to have visible output when interactive mode is off, so that we can at least keep track of the bpm value?

