Implement profiling for any thread

[historic_bruno]

Currently the profiler is restricted to the main thread, so e.g. scripts that run in other threads can't use the profiling functions. According to Philip, it's hierarchical and each threads needs its own hierarchy, also timings on other threads are independent of frame rendering. So perhaps the profiler should be designed to support one instance per thread, and then those threads would each use their own local profiler.

Potential areas of benefit:

• Random map scripts
• AI scripts (once multithreaded)
• Pathfinding (once multithreaded)
• ?

Also of interest: #806, which will allow script profiling with JIT enabled.

[wraitii]

Solved in [10465] thanks to Profiler2.