[2.5.x] If banned list contains "word;" it rejects every message

See: http://joomlacode.org/gf/project/joomla/tracker/?action=TrackerItemEdit&tracker_item_id=32639&start=0
Update contactemailmessage.php
Update contactemailsubject.php
Merge pull request #3068 from Hackwar/patch-6

[2.5.x] If banned list contains "word;" it rejects every message
Merge remote-tracking branch 'upstream/2.5.x' into 2.5.x