Uproot

Fixed 199: `uproot.iterate` and `uproot.numentries` skip files that don't have a TTree at the given `treepath`.

Now depends on awkward 0.7.0+ and uproot-methods 0.3.0+.

Strict dependency on the lz4 library was removed. It was difficult for some users to install and not needed for all ROOT files. If users encounter lz4-compressed or lzma-compressed ROOT files and they don't have these libraries, a message with copy-pasteable pip and conda installation commands are provided. This resolves the confusion raised in 186 and avoids 192 if possible.

The HTTPSource doesn't rely on `"content-length"` being correct if the total size is not larger than the chunk. This works around a bug where XRootD servers in HTTP mode were giving the wrong value. Issue 190.

Now `help(uproot)` returns a useful cheat-sheet. Issue 191.

All TTree access to Numpy is done through `awkward.util.numpy`, preparing for a test in which we swap Numpy for CuPy and read ROOT data directly into GPUs.

Depend on pkgconfig to try to resolve 192.

Start using the new locations for awkward default types (`awkward.util.*TYPE` → `awkward.array.base.AwkwardArray.*TYPE`).

Version 0.5.5 of awkward and version 3.2.13 of uproot are incompatible with each other because this was so unwisely moved. In version 0.5.6 of awkward, they were made visible from both locations, so that version of awkward is compatible with any version of uproot. It's only the 0.5.5/3.2.13 pairing that's broken.

It also implies that uproot, starting with this version, must now depend on `awkward >= 0.5.6` to see the TYPEs in their new location. This has been made an explicit version dependency in setup.py and requirements.txt.

Fixed 187, allowing Double32 type in jagged arrays.

Correctly interpret `std::vectors` nested within `TClonesArrays` (for Bacon).