Uproot3

PR 449.

PR 442; platform-dependence on 32-bit Windows.

* PR 426: Enable getitem for TTree to recognize cycle number.
* PR 427: Allow compressing ROOT objects which have size greater than 2^24.
* PR 428: Get pytest-error-for-skips from PyPI.
* PR 430: Add support for writing multidimensional arrays to TTree branches.
* PR 432: Add handler for `map<string,string>` to streamed objects.
* PR 435: Allow dtypes with byteorders via lists. Fixes 434.
* PR 436: Instructions to set up a development environment.
* PR 437: Clear ChunkedSource cache on explicit close.
* PR 439: Add close method to ROOTDictionary. Fixes 438.

* PR 411 Handle HTTP servers that don't support range requests.
* PR 417 Branch titles in object docstrings, especially for usability in Jupyter.
* PR 420 Avoid misleading error messages about being unable to recover baskets when the branch actually has no data.
* PR 421 Reading ROOT files compressed using ZSTD.
* PR 423 Fix a bug in HTTP handling.

Fixes issued 404 with PR 405.

Issue 399 and its fix, PR 400.