clean code: splits model-view

[jaapandre]

code and views are mixed up, should be cleaned, also more functions to generate for example the result preview

[Potherca]

I've already refactored the code to only do a single echo. It's a small step to get things separated from there.
I was thinking of just moving all markup to a separate HTML file, loading that as a DOMDocument and manipulating nodes from there (although that would make the code PHP5 only... hope that's not a problem...)

This step would also include having the styles in a separate CSS file.
(and probably putting the header in a div instead of a table... but that's a different matter entirely)

[jaapandre]

Hi, that would be nice. Please send a pull request. I like to try that, but I'll add you as collaborator later on.
php 5 is not a problem.