Added TraceLogger to get backtrace for executed queries

Added a TraceLogger that returns a backtrace for the executed query.
The backtrace returns the last 10 frames, and it also formats the frames for easy reading
Right, but this is still just a halfway solution. Just store the traces and you will save yourself a lot of trouble when you actually need to dig into the problems in detail.

The amount of memory used by the trace itself is negligible: just the GC may be heavy, but it is simple to workaround that by just resetting the traced queries every now and then.