workbook - collection of sheets

[shrek]

FYI-

http://github.com/shrek/socialcalc

attempts to enhance socialcalc with the ability to work on multiple
sheets at the same time (and load and save them) as a workbook. Its a
basic prototype, and the UI is clunky but it allows:
1) add sheet to workbook
2) del sheet from workbook
3) rename sheet in workbook (not implemented yet)
4) load and save workbook (not implemented yet)
etc..