toy-font-metrics

Copperbox revision 1827.

More work on the parser...

I've specialized the current parser to only work for v2.0 AFM format files. This is the format used by GhostScript. A one size fits all parser will be quite tricky - there are quite big differences between v2.0 and v3.0, and more differences again to v4.1 which appears to be the current revision. In fact the current parser is severely limited as AFM files can have user defined fields, so I think I'll have to make a much laxer parser that puts name-value pairs into a finite map rather than builds a syntax tree.