Verifying the ability of CPAINT to handle arbitrary charsets. The data being put in the backend is
converted to UTF-8, where non-printable characters are additionally converted to the sequence \u00xy
NOTE: The conversion to UTF-8 is performed only if the iconv extension of PHP is available
or if the input characterset is ISO-8859-1, which can be converted by other means. If both is not the
case the characters are cleaned up to form valid XML and are sent as-is. This should still work.
Without this extra conversion most browsers' XML parsers will crash.
CPAINT frontend decodes the character stream before handing it to the callback function.
standard 7bit ASCII
non printable characters
common but problematic characters