Consider edit-time highlighting in demo app

[TaoK]

While answering a question from Richard King I came across the ModelText control - turns out it's closed-source so might not be the besst choice (and may not work in NMono anyway), but it does raise the question of whether some HTML-editing control might make the demo app somewhat more compelling, turning it more into a very-lite IDE.

Other pieces to consider:

• Lutz Roeder's Writer
• Carl Nolan's Winforms Html Editor sample
• Editable DIV functionality in WebBrowser, as outlined in this stackoverflow question and also this codeproject article

A drastic option, if none of the above work convincingly, would be to consider RTF output in addition to the current HTML option. This should not be too difficult, although it would seem a little redundant. (eg: http://stackoverflow.com/questions/7458793/c-sharp-cross-platform-richtextbox-urls-or-alternative-solution)

[TaoK]

I'm generally interested in a "format-as-you-go" flow; it requires some "alone time" to do, but would definitely be a better experience for poorsql.com, it's fun to work on, and it would bring the plugins closer to "SQL Prompt" parity (still v distant I'm sure, but closer :) )