commands can only be added interactively to a watchpoint

Hi

I think this is the same problem as 
https://sourceware.org/bugzilla/show_bug.cgi?id=10079, but this bug is 
so old, it's probably forgotten.

I would like to run repeated tests through valgrind, where I am setting 
two hardware watchpoints and log the changes.
So I have tried this commands.txt:

```
target remote | vgdb
b main
c
n
n
p fifo
watch -l (int64_t [2]) *&fifo
watch -l (int64_t [16]) *&*fifo->storage
set logging enabled on
commands 2
   continue
end
commands 3
   continue
end
c
monitor v.kill
```

That could work, if 'commands' would work in script mode, which it 
doesn't. So each run I have to do some tedious typing. If  only I could 
do something like this...

```
commands 2 --script "continue\nend"
```

Ciao
    Nat!