Added StackWalker class for Windows
VolatilePtr should produce run-time exceptions with backtraces on deadlocks.
Keep blocking the thread after a failed lock.

VolatilePtr should cause a low overhead.
Attempt a cheap non-blocking lock before doing a slightly more expensive (500 ns) blocking-lock.
The VerifyExecutionTime class should warn if it takes longer than specified to execute a scope.

VolatilePtr uses VerifyExecutionTime.
VolatilePtr shouldn't require modification of the class T.
Specify timeout_ms and verify_execution_time_ms with VolatilePtrTypeTraits
Renamed VolatilePtr to shared_state
replaced read1/write1
Tidy
Makefile .depend
The trace_perf class should log the execution time of a scope and warn if it was below a threshold.
make_dump_summary.py parses files in the dump folder and creates a summary in the summary folder
Renamed shared_state classes to lower case
Tidy
Tidy shared_state.cpp.db
Use {} instead of () in constructor calls