#39 NUL chars in strings

[James Woodcock]

TinyScheme doesn't handle NUL chars in strings properly. In the C code, TinyScheme uses strlen() et al which truncate Scheme strings at the NUL character.

I have attached a patch that should fix this.

[James Woodcock]

Here is a test case. I have used it to check TinyScheme with my patch, Guile and Chicken.