just changed the import procedure a bit, hence these changes
treating 0-length as 1 makes no sense

error when only one arg non-zero length, otherwise stil figuring it out
delay recycling to avoid errors when key is NULL
do not make up keys
don't try to recycle nulls
make c.keyvcal work with NULL keys
remember we are splitting here, can't recycle NULLs
can't do mapply with NULL keys