QETLAB:Change log/v0.8

New functions

 * BellInequalityMaxQubits: Approximates the optimal value of a Bell inequality in qubit (i.e., 2-dimensional quantum) settings.
 * NonlocalGameValue: Computes the maximum value of a nonlocal game in a classical, quantum, or no-signalling setting.

Changes to existing functions

 * BellInequalityMax: Bug fix when computing the classical value of a Bell inequality using measurements that have values other than $0, 1, 2, \ldots, d-1$.
 * KrausOperators: If the zero map is provided as input, this function now returns a single zero matrix Kraus operator, rather than an empty cell containing no Kraus operators.
 * XORGameValue: Bug fix when computing the value of some XOR games with complex entries.