MkTmpdir creates a temporary directory based upon the prefix passed in.

MkTmpdir does the same work as "MkTmpdir", except in case of errors, it'll trigger a panic.

FakeHandler is to assist in testing HTTP requests.

LogInterface is a simple interface to allow injection of Logf to report serving errors.

TestInterface is a simple interface providing Errorf, to make injection for testing easier (insert 'yo dawg' meme here).