Uproot

Fixed 383.

beojan added custom behaviors for TGraph, RooCurve, and RooHist (PR 350).

jpivarski fixed `how="zip"` for branches with the same name but different numbers of items (PR 369), fixed TH3 with `dd=True` (PR 372), and various tweaks for the 2021 tutorials (PR 376).

nikoladze fixed a leaking-threads issue in XRootD (PR 338).

cozzyd added support for HTTP authentication (339).

chrisburr added XRootD version checks to navigate around bugs that have been fixed (PR 358).

jpivarski fixed a leaking-threads issue in HTTP (PR 334), division by zero in calculating the number of entries (PR 336), adjusted to the new scikit-hep-testdata (337),

jpivarski is developing the ability for Uproot to write files. At the moment, you can copy any non-TTree objects from another file or create new TObjStrings (PRs 341, 343, 344, 345, 346, 349, 352, 363).

kratsg implemented memberwise serialization for `std::pair`: PR 298, 301.

nsmith- made sources and caches pickleable: PR 302.

wiso fixed a typo in the documentation: PR 315.

henryiii cleaned up the build procedure and got Python 2.7 added to the regular tests: PR 316, 317, 319.

jpivarski fixed a bug that exposed internal JaggedArray objects (if they're empty): PR 304. Added histograms to the regular tests: PR 305. Fixed "file://" handling on Windows: PR 328.

jpivarski also started developing file-writing (though it's not ready yet): PR 320, 322, 329, and fea04add86aa6efff4f48724ef5f940af427aeee.

nsmith- improved TTree read-performance (mostly memory use): PR 296 reduces the reference count of big arrays in Future objects, PR 297 removes cycles and reduces reference counts of more arrays early, particularly in TBaskets.