attachable function for determining “near misses”

This is a system function that determine whether a failed match of a monitored rule constitutes a near miss.

**Note:**This function is attachable (see defattach).

General Form: (brr-near-missp msgp lemma target rcnst criteria-alist)

where msgp is `monitor`ed `monitored-runes`.

The function determines whether the pattern of the lemma
“almost” matches the target, i.e., whether a “near
miss” has occurred. The function is only called if the exact match
failed. The built-in version of this function checks the criteria described
in `monitor`. If a near miss has occurred, the result is either `msg`) object describing the near miss. If a near
miss did not occur, the result is