Xhtml disabler

[naNuke]

Switch between xhtml tag closers /> to >

This is pretty much open to discussion, I use it in my project and it works perfect so far :)

[hkdobrev]

Ideally I would prefer an opinionated parser which would produce HTML only, but since Parsedown produces XHTML at the moment, this could be a good move keeping backwards compatibility.

[naNuke]

Xhtml is practically dead on modern web nowdays but since parsedown supports dinosaur version of php like 5.2, some people might actually expect to use xhtml, which is fine imo. The switch code doean't add anything that would break parsedown's awesome performance.

[erusev]

I'll have to think about this.

[laukstein]

@aidantwoods please add this or best replace closer tag /> with >. Know that XHTML isn't no longer supported in HTML5 by spec.