subrepo: Update .hgsubstate in case of deleted subrepo
When a subrepo is deleted from .hgsub, it also needs to be removed from
.hgsubstate. Previous code was updating .hgsubstate only in case of newly or
modified subrepo.
Do not use osutil.c with python 2.4 and Windows (
issue1364)
Windows python 2.4 os.stat() reports times including DST offset, while osutil.c
reports the correct value, which makes status() systematically compare files
content. This bug is fixed in python 2.5. Using osutil.py instead of osutil.c
is 4x times slower on large repositories but current code is completely
unusable. Given few people are likely to use python 2.4 on Windows this
solution was considered a good trade-off compared to more invasive solutions
trying to address the offset issue.