[Seaside] new version of ROE

[Avi Bryant]

Based on the feedback from Danil and Brett, I've just put a new, 
port-friendly version of ROE on SqueakMap.  This is mostly a tweaked 
version of what Danil posted, and includes:

- getting rid of the string/symbol messiness in the unit tests
- getting rid of {} and caseOf:
- a new SQLRelation abstract class that PostgresRelation subclasses
- #exec:/#query: distinction
- an #sqlPrinterClass hook that lets SQLRelation subclasses use a 
custom printer
- all attribute names are searched for case-insensitively (looks like 
oracle needs this)

I haven't yet adapted any of the support for other databases (Oracle 
from the VW port, ODBC from Dolphin).  If you guys want to send me 
fileouts of SQLRelation subclasses and supporting SQLPrinters that work 
with the new version, I'll be happy to include them in the next 
release.

If I missed something important, let me know.

Cheers,
Avi