posixfile: remove posixfile_nt and fix import bug in windows.py
The posixfile_nt class has been superseded by posixfile in osutils.c,
which works on Windows NT and above. All other systems get the regular
python file class which is assigned to posixfile in posix.py (for POSIX)
and in the pure python version of osutils.py (for Win 9x or Windows NT
in pure mode).
util: import random, missing since
ea82a23cf887
clone: try updating to the actual changeset specified in options
When cloning with the -r option or # url format from a tag the destination
repo most likely won't have the tag. We can save the lookup result to get to
the correct parent anyway. Similar to
issue1306, but for tags.