Merge pull request #138 from anubhavvardhan/quantum_circuit

Added unitary matrix calculator for arbitrary qubit circuit
Merge pull request #139 from anubhavvardhan/quantum_circuit

Bug Fixes
Merge pull request #140 from anubhavvardhan/quantum_circuit

control, target changed to target[] in swap gates
Merge pull request #142 from anubhavvardhan/quantum_circuit

Resolving given qubit circuit to specified basis.
Made qutip.entropy.concurrence work for pure states in addition to density matrices. Improved error checks.
Merge pull request #143 from jrjohansson/patch-concurrence

Patch qutip.entropy.concurrence for pure states
added entangling_power function
add entangling_power to __init__
unit tests for entangling_power
added reference for entangling_power
added import of qutip.qip.gates.swap in qutip.entropy for use in entangling_power
increased entangling_power test tolerance
added import of future division for py2 compatibility, and reduced tolerance again
Merge pull request #144 from jrjohansson/add-entangling-power-function

Add entangling power function
Merge pull request #145 from anubhavvardhan/quantum_circuit

Add unit test for gate resolution
Merge pull request #146 from anubhavvardhan/quantum_circuit

Change the structure of resolve_gates to make it more inuitive
Merge pull request #147 from anubhavvardhan/quantum_circuit

Fixing circuit.py
Merge pull request #148 from anubhavvardhan/quantum_circuit

Modified QubitCircuit class to use just a single gate list and fixed the unit tests accordingly
Merge pull request #149 from anubhavvardhan/quantum_circuit

Added SWAP to ISWAP gate conversion in resolve_gates
Merge pull request #150 from anubhavvardhan/quantum_circuit

Added method adjacent_gates to circuit.py.