qa: fix cleanup trap in qa/898 from leaving tmpfile remnants
qa: fix cleanup trap in qa/067 from leaving tmpfile remnants
build: default to a more professionally named webapps directory

Someone in storage-land complained that "jsdemos" doesn't really
give off a confident vibe when people are accessing the webapps.
Set the default pmwebd resource path to something a bit more like
what people would expect to see, giving 'em a warm fuzzy feeling
and making it at least look like we know what we're doing.

Of course, its still configurable to whatever anyone wants - just
the default setting being tweaked here.