bindings: Generate HdyDialog, HdyComboRow, and HdyHeaderGroup
requested to merge BrainBlasted/libhandy-rs:wip/christopherdavis/generate-dialog-and-comborow into master
Bindings for these were missing during the upgrade to 0.0.7.
This adds them to the right Gir files and generates them.
Closes #2 (closed)