Awkward

ianna fixed class names in the documentation (PR 860).

agoose77 fixed `ak.is_none` (PR 864).

drahnreb made Parquet lazy-loading only build Forms for requested columns (PR 867).

agoose77 and drahnreb together made idioms like `x["z"] = None` work correctly by assigning a column of Nones (PR 880).

jpivarski fixed some union-simplification issues in getitem-field (PR 870). Also fixed various bugs to enable Numba JIT-compiled functions to iterate over VirtualArrays created by lazy-reading Parquet (PR 871). Fixed a relic of the `ptr().get()` → `data()` transition for kernel interfaces (PR 877). Fixed some null-type issues with Arrow/Parquet columns (PR 878). And fixed matrix multiplication of a vector as an Awkward record (PR 868).

HenryDayHall fixed a string inequality comparison (826) and added a dtype argument to ones/zeros/full_like functions (814).

agoose77 fixed an error in matrix multiplication when one array is NumPy (847).

henryiii cleaned up the setup.py (831), the setup.cfg (834), and CMakeLists (833).

trickarcher finished JAX integration, merging it into the main codebase (793 and 855).

ianna finished TypedArrayBulder implementation, leaving only the high-level interface (769), fixed an `argsort` bug with masked arrays (850), and arrays of complex types in `concatenate` (858).

jpivarski fixed unflattening `axis>0` with a scalar (820), ak.Record's "promote to subclass" (825), adding a handler for pyarrow's `DataType(null)` and `ndim != 1` boolean arrays in `to_arrow` (837), allowed scalars in `ak.zip` to make an ak.Record if they're _all_ scalars (839), and removed "ignore" from some Flake8 complaints (844).

The result of broadcasting a UnionArray now includes all types of the original array, regardless of whether they appear in the broadcasted version. This fixes the types of empty arrays (so that `+` still works on custom behaviors, etc.). PR 816.

ianna fixed `ak.argsort`'s type for empty arrays. PR 812.

Issue 805/PR 808, empty case when broadcasting UnionArrays.

Same as [1.3.0rc4](https://github.com/scikit-hep/awkward-1.0/releases/tag/1.3.0rc4). Deploying as a full release because issue #859 was encountered twice (before as 836), so it's a common problem.