Fix #317 User Merge bug/problem
Make sure users aren't on their own buddy/ignore lists
Call array_diff() before implode()

I missed that.
trim() imploded lists

This _should_ work as we can never have a comma at the beginning or end...
Remove users on ignore list from buddy list
Merge pull request #386 from nmalcolm/fix-317

Fix #317 User Merge bug/problem