Update selectboxes/jquery.selectboxes.js

[rhett-wang]

I am trying make some change for addOption

if the first param object( json ) has value and text, then put others key-value as attribute of option.

Then options of select box can carry more data.

I am not a jQuery expert, so can you review my updating?

You may have better solutions.

and hope you add this kind of function in your next release.

Thanks

sincerely
Rhett