mercurial/repo.py

change lock format to let us detect and break stale locks.

old style: symlink to pid
new style: symlink to hostname:pid

if lock code finds new-style lock, it breaks lock if locking pid is on
same machine and pid is not alive.

otherwise, lock is left alone.  this makes locking code safe with
old-style locks and with locks on other machines.

new code makes server part of mercurial more robust in case machine
crashes, power fails, or crazy user does kill -9.

# repo.py - repository base classes for mercurial
#
# Copyright 2005 Matt Mackall <[e-mail]>
#
# This software may be used and distributed according to the terms
# of the GNU General Public License, incorporated herein by reference.

class RepoError(Exception): pass