Attempt at typed nils, doesn't work.
Explicit ErrorIsNil checker.
Merge pull request #40 from howbazaar/reject-typed-nil

Implement ErrorIsNil checker
Split DestroyWithLog in platform specific files because you cannot send os.Interrupt on windows
Changed gc.Equals to jc.SamePath for a test
Merge pull request #41 from bogdanteleaga/mgo-windows-fixes

Mgo windows fixes
Merge branch 'master' of https://github.com/juju/testing into codec-checkers