Matches REGEX against TARGET-STRING as often as possible and
returns a list of the substrings between the matches. If
WITH-REGISTERS-P is true, substrings corresponding to matched
registers are inserted into the list as well. If OMIT-UNMATCHED-P is
true, unmatched registers will simply be left out, otherwise they will
show up as NIL. LIMIT limits the number of elements returned -
registers aren't counted. If LIMIT is NIL (or 0 which is equivalent),
trailing empty strings are removed from the result list. If REGEX
matches an empty string the scan is continued one position behind this
match. If SHAREDP is true, the substrings may share structure with
TARGET-STRING.