cbor: teach the encoder to handle python `long` type for Windows The tests for 2**32 and -7000000000 were blowing up, complaining about not knowing how to encode type 'long'. sys.maxint tops out at 2**31-1 on Windows, but I guess is 2^63-1 on Linux? I *think* we're OK on the decode side, as there is an assertion that the decoded value is equal to the original primitive value. I opted for the pycompat alias instead of swallowing the NameError because the vendored cbor package uses an alias, and I see at least pywatchman and templatefilters open codes their own aliases.

buildrpm: remove TODO that looks done to me Differential Revision: https://phab.mercurial-scm.org/D4494

buildrpm: fix embarassing bug in shell variable expansions `$distance_$node` looks up and concatenates `$distance_` and `$node`. `$distance_` is empty, so we were getting the node without the distance. Using the curly braces makes our intent explicit and produces better-versioned RPMS. Differential Revision: https://phab.mercurial-scm.org/D4493