[merge][#251352] better messages for illegal 'log -m' arguments

[Bundle Buggy]

Bundle Buggy has detected this merge request.

For details, see: 
http://bundlebuggy.aaronbentley.com/project/bzr/request/%3Ce01316480903231851va0ab12cyea9a143e24da0691%40mail.gmail.com%3E
Project: Bazaar