first pass at swap mapper, bugs fixed, acknowledge
first pass at swap mapper, bugs fixed, acknowledge

QISKit/qiskit-sdk-py,ChristopheVuillot/qiskit-sdk-py,atilag/qiskit-sdk-py,ChristopheVuillot/qiskit-sdk-py,QISKit/qiskit-sdk-py,QISKit/qiskit-sdk-py,ChristopheVuillot/qiskit-sdk-py,atilag/qiskit-sdk-py,atilag/qiskit-sdk-py