Fixed mutex::is_locked_by_me() on Gcc

Gcc's thread implementation fails to compare null thread id. So, an
auxiliary variable was created to tell if the mutex is locked or not.
- Code branches to TinyThread++ if C++11 is not supported. C++11 is used otherwise.
- Linux support is back (tested on ArchLinux)
- Better Win64 support (tested on MSVC 2012)
- tracey::mutex() rewritten because of bug in GCC C++11's std::thread::id(). Should be backward compatible (thanks to André Puel!)
- tracey::demangle() sorted by priority now.
- Couple of bugs fixed (thanks to marton78!)
- Clean up. 200 LOC removed.
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Demangle stack traces on MacOSX
Merge pull request #4 from marton78/master

Demangling stack trace on Mac (@marton78)
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Update README.md
Update README.md
Update README.md
Update README.md