rust-status: improve documentation and readability...
rust-status: improve documentation and readability
This patch is 2/3 in the series to improve the dirstate status code. It adds a
number of common type aliases to add more obvious semantics to function
signatures, improves/adds documentation where necessary and improves one or two
patterns to be more idiomatic.
Differential Revision:
https://phab.mercurial-scm.org/D8662
