extend MarkPadRT to work with ReStructuredText

[scrumit]

Before I pull the repo and look more carefully, I thought I'd suggest this and see what the response is like.

Although Markdown is the front runner it is diverging and ReStructuredText appears to have advantages. I refer to exhibit 1, a common subset for the two.

What do people think? I'm not (yet) asking other people to do anything. I'm perfectly capable of writing code.

Having said that, I'm very happy with CodePadRT on my (wife's) Lenovo Yoga 11. It's better than WriteDown! on the mac, which appears to crash at inopportune moments.