LP#1781480: Closures remeber values in subtle ways...

LP#1781480: Closures remeber values in subtle ways...

... and we must take care to avoid that.  This commit forces a state variable
to be statically assigned an empty list rather than depending on the idiomatic
undef to vivicate an empty list.  This is important for all OpenSRF methods,
and manifests here as a search "remembering" a previously chosen location
group.  A comment to that point is included for our future selves.

The core probably arises from the fact that, in the end, OpenSRF methods are
generated closures.

Signed-off-by: Mike Rylander <mrylander@gmail.com>