fixed bug in author_tool

Hi Joel,

 bin/galileo author_tool
 says to me:
 [Wed Jul 17 16:32:26 2013] [debug] Reading config file "/home/holger/workspace/Galileo/galileo.conf".
 No command: Galileo::Command::author_tool=HASH(0x9ce505c)

 after the change it works as expected now

Best regards from Dresden
Holger