1.1.3dev: Made equal messages that differed by a single word or whitespace. Refs #10207.

This revises some changes from [13211] and 13212].


git-svn-id: http://trac.edgewall.org/intertrac/log:/trunk@13221 af82e41b-90c4-0310-8c96-b1721e28e2e2