*INCOMPLETE* Rewriting thread (runnable and runnable_thread removed)
Solution filters fixed
minor fix (linux) for testthread
minor fix (linux) for intrusive_ptr
Removed atomics from reference_counted.
stack_trace: linux fix fixed for windows
exception::fetch_stack made more robust against memory problems
Linux dead-lock with stack_trace fixed
Linux and Unicode problem
Minor fixes for gcc 4.6.3
