Custom class should go directly on tag for inline markup in dzslides backend

[mojavelinux]

Currently, the inline_quoted template puts a custom class on a nested <span> element for inline markup such as strong, emphasis, monospace, etc. For example:

[myclass]*text*

becomes

<strong><span class="myclass">text</span></strong>

This output inherits from the HTML 5 backend in AsciiDoc. But we don't have to follow it for the dzslides backend. Instead, the class should be put directly on the tag, when there is one, such as:

<strong class="myclass">text</strong>

This just makes sense and makes styling a heck of a lot simpler.

[LightGuard]

👍