this code should just check that the TE is not assigned, not that its topic is not assigned; switching this code reflects a decision I also made in Sep 2012, see https://github.com/lml/ost/commit/522be67e97efe5c89c0b2448535ca910bff07d1a#diff-908e91a53f0aec8ed92e927ed25d6878 and https://github.com/lml/ost/commit/453aabcc3d988c1ecf3c0972cd343ae57c23055f#diff-908e91a53f0aec8ed92e927ed25d6878
Merge branch 'master' of github.com:lml/ost