add option forceSelfClosingEmptyTag

[cnoll]

Hello,
I couldn't find a option to force the self-closing of empty tags, so I decided to do my first contribution on github.
I hope it works well :)

Option: forceSelfClosingEmptyTag

Input:

<root>
    <empty></empty>
</root>

Output:

<root>
    <empty/>
</root>

Kind regards
Constantin

[chrisbottin]

Thanks for the contribution @cnoll. The PR is now merged and a new version will be published shortly.

[chrisbottin]

Option available in version [email protected]