More work on Gen_Regexps
Fix a few free variable bugs, get digits-of-e1 working
Improve the evaluation, with a bit of a hack for case on a variable, since we do know it's value
Add some commented out transformations that I added while working against exp3_8, but are't required
Remove some redundant jail's from exp3_8
More consistent treatment of jails
Add some notes about jails, and how to proceed