v1.6.0

CL-QUIL updates:

• We included a conveniency chip constructor with all-to-all connectivity.
• quilc will now compile parametric PHASE gates to parametric RZ gates. As a consequence, more Quil programs emitted by pyQuil / Grove will work out-of-the-box with parametric compilation.
• The handling of dead qubits has improved, resulting in fewer complaints about logical qubits being initially assigned to physical qubits lying on different connected components of a disconnected chip.
• More fractions of pi get pretty printed upon request.
• Various speed improvements.
• Approximate compilation, which replaces the previous contents of src/compilers/optimal-2q.lisp. This new suite of functions produces from all circuits of a particular shape the 'nearest', in the sense of average state fidelity, to a given program. This can then be used to either perform approximate compilation or to perform traditional optimal compilation (by rejecting all results with imperfect fidelity distance).

quilc updates:

• --log-level and --quiet help control the verbosity of quilc's server mode output.
• quilc checks for an SDK update on start, so that users are reminded when there's an update available.