Focused chat on Add/Edit

Resolves #1046.

http://jenkins.buttonweavers.com:8080/job/buttonmen-AdmiralJota/231/
So, http://stackoverflow.com/questions/511088/use-javascript-to-place-cursor-at-end-of-text-in-text-input-element suggests doing:
```
$(element).focus(function(){
  this.selectionStart = this.selectionEnd = this.value.length;
});
```

as an alternative to the hack you use, which is suggested earlier in that post.  Did you try that?