Draft: Performance improvements for qtDescriptivePhraseModel
requested to merge chart3388/smtk:feature/phrasemodel-performance-improvements-adjustments into master
Implemented QAbstractItemModel::canFetchMore() and QAbstractItemModel::fetchMore() on qtDescriptivePhraseModel for checking if the subphrases are built and telling the phrase to build itself respectively. The side effect of this is the view will now drive when subphrases should be built for the first time.
Added numberofSubphrases function to derive the number of expected subphrases when the subphrase have not been built yet.