bug 153, 1066: Convert properties of SMJS bookmark to/from UTF-8.
SpiderMonkey uses UTF-16 and the strings in struct bookmark are in
UTF-8. Previously, the conversions behaved as if the strings had been
in ISO-8859-1.
SpiderMonkey also supports JS_SetCStringsAreUTF8(), which would make
the existing functions convert between UTF-16 and UTF-8, but that
effect is global so I dare not enable it yet. Besides, I don't know
if that function works in all the SpiderMonkey versions that ELinks
claims to work with.