First production release!

Release candidate 2 for v1.0

Release candidate 1 for v1.0

- New quantum circuit synthesis example.

- Documentation updates.

- Bug fixes and documentation updates.

Bug fixes.

- Redesigned hybrid expression backend; Penalty terms for abstract te…

…nsors

Allow hybrid indexless/Einstein expressions; Various initializers for…

… abstract tensors.

Merge pull request #110 from yhtang/feature/vectorize-broadcast

Rewrite vectorizer using `broadcast_to`.

Pre-release update. Tons of new features.