Log Message:
Update p5-Exception-Class from version 1.29 to version 1.30.

Pkgsrc changes:
- Adjust LICENSE

Upstream changes:
1.30 Mar 20, 2010

- Added the ability to create light weight exceptions, which don't record a
  stack trace or any other context info (time, pid, etc.). This is done by
  setting $class->NoContextInfo to a true value for the exception class. Based
  on a patch by Graham Barr. RT #54826.