Allowing external configuration

I re-worked the autotrigger branch to allow external configuration while keeping sane defaults.

```javascript
var svg4eb = {
  fix = 'replace', //choose the fix type based on external testing etc
  replaceExt = '.svg', //allows replacing with inline svg when the browser supports inline svg as image
}
```

I'm not familiar with all the javascript shorthand you are using. Also I tend to opt for verbosity for readability. That being said, I tried to match your styling as much as I could.