(FP, RK) ArViz: Replace Coin timer by QtTimer to fix ArViz from freezing (update() would not be called in some cases)

- This prevents expensive cloning if elements do not have stable names
- This is the case, e.g. for grasp candidates

Allow disabling ArViz introspection via check box (disabled by default). Compile-enable ArViz introspection

+ Timings are now calculated for each update
+ Some aggregated timings are reported to the debug observer