inotify: improve error messages * prefix messages by inotify-(client|server) * make sure that all warning and abort messages use the same format. * in the case where inotify.sock is an old broken symlink, say so and abort instead of trying to overwrite the already existing link

% fail
abort: inotify-server: cannot start: .hg/inotify.sock is a broken symlink
inotify-client: could not talk to new inotify server: No such file or directory
abort: inotify-server: cannot start: .hg/inotify.sock is a broken symlink
% inserve
% status
? hg.pid