dirstate-item: add a `from_v1_data` constructor
This class method is dedicated to building a DirstateItem from the data
available in the "dirstate-v1" format. Since that format is frozen, this
constructor will never change (unlike the `__init__` one).
Differential Revision: https://phab.mercurial-scm.org/D11118
docutils
# Pinned to an old version because 0.20 drops Python 3 compatibility.
dulwich < 0.20 ; python_version <= '2.7'
dulwich ; python_version >= '3'
keyring
pygit2 ; python_version >= '3'
pygments
# Need to list explicitly so dependency gets pulled in when
# not running on Windows.
pywin32-ctypes
windows-curses