mail: use safehasattr instead of hasattr

url: replace uses of hasattr with safehasattr or getattr

subrepo: use safehasattr instead of hasattr Some of these instances could be rewritten as clever getattr(x, y, default) ladders, but that felt like it impeded readability too much to be worth the modest efficiency gain.

statichttprepo: replace hasattr with getattr

walkrepos: use getattr instead of hasattr for samestat

revlog: use getattr instead of hasattr

lsprof: use getattr instead of hasattr

keepalive: use safehasattr instead of hasattr

hgweb: move remaining hasattr calls to safehasattr

wsgicgi: use getattr instead of hasattr

httprepo: use getattr instead of hasattr

help command: use safehasattr instead of hasattr