sqUnixCharConv.c: correct path encoding
sqUnixCharConv.c: correct path encoding

- Use UTF8 instead of MacRoman when converting paths sq to ux
- Convert decomposed to precomposed UTF8 when convert ux to sq

OpenSmalltalk/vm,OpenSmalltalk/vm,OpenSmalltalk/vm,OpenSmalltalk/vm,timfel/squeakvm,timfel/squeakvm,timfel/squeakvm,timfel/squeakvm,OpenSmalltalk/vm,OpenSmalltalk/vm,OpenSmalltalk/vm,OpenSmalltalk/vm,timfel/squeakvm,timfel/squeakvm,timfel/squeakvm,timfel/squeakvm