Added send_hash option for more security
Fixes for last commit
Merge pull request #210 from loblao/master

Added send_hash option for more security
Merge branch 'master' of github.com:Astron/Astron into enhancement/messagedirector-cleanup
MessageDirector: Reverse the argument order of ChannelMap's lookup_ methods.
Merge pull request #211 from Astron/enhancement/messagedirector-cleanup

Clean up the Message Director
Logger: Make the logging facilities thread-safe.
MessageDirector: Make ChannelMap thread-safe.