BitMagic release v3.4.0

Release Notes: BitMagic 4.0.0

Implemented 64-bit address mode for indexing problems with more than 4 billion elements.
#define BM64ADDR to enable the new mode or use
#include bm64.h

Known limitations: it only supports 48-bit (2^48-1) elements, you cannot use both 32-bit and
64-bit address modes in one compile unit (implementation is based on pre-processor)

Added new example to explain how to enable 64-bit mode.
https://github.com/tlk00/BitMagic/blob/master/samples/bvsample01_64/bvsample01_64.cpp

Added bm::bvector<>::erase() method to delete a bit in bit-vector

Added bm::bvector<>::shift_left()