toy-font-metrics

Copperbox revision 1825.

I've added decent white-space handling courtesy of cut down versions of Parsec's LanguageDef and TokenParser modules / datatypes. Credit and thanks to Daan Leijen - Parsec is a truly exceptional library particularly in the details like the tokenizer / white-space handling and the expression table parser. Its a pity that white-space isn't configurable in the LanguageDef so I could make line oriented parsers (whiteSpace chomps newlines).