C++ support added

0.2.1

add extern "C" to use pstrace in C++ applications. renamed global logger

Basic functionality of stack unwinding including retrieval of values of variables from stack trace

Functionality of this release:

1. Simple unwinding using libunwind
2. Advanced unwinding using libdwarf
3. Support of all C/C++ base types plus typedef, const etc modifiers
4. Support of pointer and pointers to functions
5. Pointer validation
6. Retrieval of values of variables an function arguments in from stack trace and DWARF information

CFA calculation and usage added

v0.1.0

small readme formatting changes