Used to find backtracking Slinq usage.

If DETECT_BACKTRACK is defined, backtrack detectors will lock a reference context and test the backtrack state on every Slinq operation. This will severely reduce performance and should only be used for debugging purposes.

If DETECT_BACKTRACK is not defined, detection operations will not be compiled into the application.

Note: Backtrack detection does not work reliably across multiple threads. If pooled objects are shared or passed between threads, external locking and/or ownership management is the repsonsibility of the user.