V8 based profiling

The declarative nature of QML makes it sometimes very hard to understand which piece of code is executed at a given point in time. This is especially true if code frequently triggers binding updates even though the respective object is not visible. We already started working on a simple profiler that allows developers to track how much time the QML engine spends while compiling, evaluating bindings, painting or handling events. This solution however, should only be seen as intermediate.

The real solution, meaning more in-depth profiling of JavaScript code on a function level requires deep integration into the js machinery and is therefore postponed until the switch to V8 is completed (same as for memory analysis tools).