largefiles: avoid a crash when archiving a subrepo with largefiles disabled
This path is also used for extdiff, which is how I crossed paths with it.
Without this, an AttributeError occurs looking for 'lfstatus' on
localrepository. See also
d414c28db84d.
The other archive method is for the archival.py override, so it doesn't need to
be special cased like this. (It looks like it is only called for the top level
repo.) Likewise, the transplant override is also for commands.py. The other
overrides set lfstatus before examining it.
patchbomb: make getaddrs function easier to work with
Prior to this the return value was potentially None, a string, or a
list of strings. It now always returns a list of strings where each
string is always only one email address
patchbomb: look for non-empty publicurl, not a non-None one
Otherwise it's impossible to turn this feature back off, which is
making writing of tests awkward.