Impossible to set output presision to 0 (no fractional part)

On big images (1000x1000) there are no needs to have fractional part in paths. But SVGO allow only 1 digit minimum after dot.

I did a quick test with regexp:

``` javascript
glyph.d = glyph.d.replace(
  /\d+\.\d+/g,
  function (match) { return Math.round(match) + ''; }
);
```

~20% profit.
