setup.py: also copy the lib and headers in develop mode
setup.py: also copy the lib and headers in develop mode

Follow-up to b491c577e971201410064bdf9362273376cd6119

chubbymaggie/pyvex,angr/pyvex,0xbc/pyvex,angr/pyvex,chubbymaggie/pyvex,0xbc/pyvex