fix(all) log.Debug -> log.Debugf
Merge pull request #241 from jbenet/fix/log-debugf

fix(everything) log.Debug -> log.Debugf
remove dagwriter in favor of new importer function
address comments from PR
Add testutil package and function to generate a dagservice
check osxfuse version. Fixes #202.
benchmark secure channel
fix bug
implement signed pipe and add blowfish cipher to supported suites
add blowfish code and refactor pipes and duplex a little
msgio pooling first hack
moved pipes package
Reenable secure channel code
shrink msgio buffer size to decrease memory pressure
more memory tweaks
cut down on allocations
address comments from PR
remove sha1 from hmac hash suite options
dagservice interface fix
some small cleanup of logging