issue2551331 - Fix repeat first/last methods. The first() and last() methods for a variable defined by tal:repeat now work as documented. There is an undocumented same_part() method for repeat. It is called by first/last and can cause them to return true when not at an end of the Iterator sequence. I wrote a treatise on that function and what it does. I have no idea why it does what it does. Added tests for roundup/cgi/ZTUtils/Iterator.py Also fixes issue with roman() found while writing tests. lower wasn't being called and it was printing the lower() method signature. Doc updates in references.txt to come in a future checkin. Clarifying the repeat methods led to finding/fixing this.