Try removing sorting from PhraseModel
Since SMTK now allows a QSortFilterProxyModel in between the qtDescriptivePhraseModel and each view, we may be able to avoid sorting phrases as they are inserted. We should try removing sorting and have the subphrase generator append new subphrases to the end of its list. This may cause some issues with PhraseModel::updateChildren()
since it relied on sorted phrases to compress observer events.