moved unrelated tests out of web module

in the process, fixed stream capturing

unfortunately, this doesn't work properly yet: run individually, each
test module passes - but taken together, there's CWD-related weirdness
refactored tests to use a single shared instance

unfortunately, it proved impossible to provide a separate instance to
each test module without introducing tons of complexity and headache

so now all tests use the same instance, which means they have to be wary
of intereference by previous tests (I opted not to reset store contents
and tagdex database as that again would introduce complexity; YAGNI?)

thanks to @cdent for graciously assisting in the discovery process