Log Message:
Update to 0.2.5. From the changelog:

This release localizes $! (ERRNO) for internal operations that
change it, as suggested by Felipe Gasper. For the same operations,
it also localizes $^E (extended OS error).

Library files:
- Localize $! and $^E for internal operations that change them.
Tests:
- Check that bare test blocks leave $!, %!, and $^E unchanged,
  but that blocks that modify $! and $^E still do so.
Also:
- Added Module::Build to the configure_requires.
- Fix emacs mode line on t/14-leaks.t.
- Better comments in lib/Test/Trap/Builder.pm.