Skip over CDATA

[mniip]

Addresses #1

• Don't fail the parse if we run into a CDATA.
• Do the same to CDATA as we do to comments: leave it up to the downstream user to parse them.

[mniip]

@ndmitchell gentle prod?

[ndmitchell]

Thanks for the patch. I reviewed it by eye and it looks great. Can we get a test in https://github.com/ndmitchell/hexml/blob/master/src/Main.hs as well? It's pretty subtle doing this coding, and a test would give a lot of confidence.

I'm afraid I'm going to be too busy to land over the next 2 weeks, but will endeavor to do it when I'm free again after that.

[mniip]

@ndmitchell ping?

[ndmitchell]

Thanks! I released Hexml 0.3.5 with this change.