LibBirch now links in pthread if found, attempting to address occasional runtime error on initialization of static local variables after compiling with gcc: terminate called after throwing an instance of '__gnu_cxx::recursive_init_error'.
LibBirch now links in pthread if found, attempting to address occasional runtime error on initialization of static local variables after compiling with gcc: terminate called after throwing an instance of '__gnu_cxx::recursive_init_error'.

lawmurray/Birch,lawmurray/Birch,lawmurray/Birch