Make the compiler warn you of deprecated Qt features

QT_DEPRECATED_WARNINGS is a keyword that can be used in your Qt's project files (.pro) so qmake makes your compiler emit warnings if you use any feature of Qt which as been marked deprecated. The exact warnings depend on your compiler, but it'll be easy to spot any location in your source base that might be affected for any Qt's API changing soon.

Qt Mobility: new APIs for mobile devices

As a result of Nokia's commitment to extend Qt Framework to more and more platforms, specially mobile devices and telephones, they released a new set of APIs called Qt Mobility.