Changed target & control to targets[] in swap gates
Changed call parameters in swap gates
Changed unit tests involving swap gates
Fixed bug in swap gates
Fixed gate_expand 2_to_N
Fixed gate_expand 2_to_N
Fixed qft_steps
Fixed bug in qft_steps
Fixed bug in swap gates
Fixed unit test for 3_to_N
Merge pull request #140 from anubhavvardhan/quantum_circuit

control, target changed to target[] in swap gates