v1.7.0

Improvements in this release include:

• quilc now supplies a --host CLI option which controls where it will listen for incoming connections.
• Improved numerical stability: the functions collinearp, which tests whether two complex unit vectors are collinear, and convert-su4-to-su2x2, which produces a factorization of a 4x4 unitary into a Kronecker product, have significantly improved behavior near "bad" values, which tamps down the number of random failures users see on good input.
• Improved error messages: in addition to a scattering of other improvements around the code, we now include line numbers during parser errors.
• We've removed PRAGMA EXPECTED_REWIRING and PRAGMA CURRENT_REWIRING from the output of quilc's compilation routines. These never meant much to machines and were instead intended for users to read, and so they've been downgraded from PRAGMA directives to comments.
• The test suite has been variously improved, especially by amending a "faithfulness test" in the quilc test suite that wasn't actually checking anything. (Thanks, @appleby!)
• There's now an internal option to print complex numbers in polar form.