Added test for EACH - PRESENT-SYMBOLS with NIL iteration variable.
Added test for EACH - PRESENT-SYMBOLS with NIL iteration variable.

clasp-developers/SICL,vtomole/SICL,vtomole/SICL,vtomole/SICL,vtomole/SICL,clasp-developers/SICL,clasp-developers/SICL,clasp-developers/SICL