Return information about the last error which occured for
<name> (where <name> is a valid name from the wiz list).
Result is an array of four elements: the filename of the
program where the error occured, the linenumber in the
program, the error message (runtime error messages usually
start with a '*'), and a numerical flag (the 'forget flag') if
the error information has been queried already.
If there is no error stored for the given <name>, 0 is
returned.
After querying the error information, the forget flag is set,
unless a 0 has been passed as <flag> argument to the efun.