[BUG FIXES]
Fix compilation on 5.8. Reported by ether. (doy)
A custom error class caused a warning when the class that used it was made
immutable. Reported by Maroš Kollár. RT #71514. (Dave Rolsky)
[ENHANCEMENTS]
- The enum type will now allow single value enumerations. Previously, two or
more values were required. (rjbs)