I've created (and merged) initial version of cordova working on harmattan@qt5 (https://github.com/cordova/cordova-qt/pull/15). Base version of qt5 can be fetched from lauromoura repo, but you also need to compile some missing modules by yourself (qtsystems, qtfeedback, qtsensors).
For now webkit-snapshot from this repo is used, but I'm thinking about compiling more recent one (still no success because of some compile errors at harmattan, I need to find either the reason or the most recent compilable version). -- Regards, Denis Kormalev