MKHTML Make char string into valid html string.
strout = mkhtml(strin)
Replaces soem special characters with codes '%number'
Special HTML symbols are encoded as hex value with ISO 8859-1 Latin alphabet No. 1
http://www.ascii.cl/htmlcodes.htm:ISO 8859-1 Latin alphabet No. 1
'%' becomes %25
' ' becomes %20 (space)
'|' becomes %7C
'/' becomes %2F
'<' becomes %3C
',' becomes %2C
'(' becomes %28
')' becomes %29
''' becomes %27
See also: ISLETTER, MKVAR, MKTEX