Bump version to 0.5.1

Bump to 0.5.0

Bump koan-engine for bugfix

Thanks to Manas Karekar for reporting.

Merge pull request #39 from sl4m/clojure-1-5

Updates to Clojure 1.5.0 final

Bump to 0.4.7 for line number in message

Bump version for zipfile upload