Solving 'Elements Of Programming Interviews' in Golang.
[5.1 - Compute parity of 64-bit unsigned integer] (http://codingberg.com/golang/interview/compute_parity_of_64_bit_unsigned_integer)
[5.2 - Swap bits of 64-bit unsigned integer] (http://codingberg.com/golang/interview/swap-bits-of-64-bit-unsigned-integer)
[5.3 - Reverse bits of 64-bit unsigned integer] (http://codingberg.com/golang/interview/reverse-bits-of-64-bit-unsigned-integer)
[5.4 - Find the closest integer with same weight] (http://codingberg.com/golang/interview/find-closest-integer-same-weight)