Feature Have to_int(buffer) return meaningful values

[heeheehee]

> ash buffer b; b.append("4"); to_int(b);
Returned: 0

> ash buffer b; b.append("4"); to_int(to_string(b));
Returned: 4

I would like it if this conversion were automatically applied, since it took me a while to figure out why

string str = "9,876";
replace_string(str, ",", "").to_int();

wasn't doing what I expected.