Fix #1069 use expected jquery with externalized mainline tiddlywiki

We do this by:

* getting jquery from the tiddlywiki site
* naming it twjquery.js
* changing the externalized html file so it points to the right
  jquery

Another option would have been to get files with different names
saved at the tiddlywiki site. This wasn't done because the expectation
is that eventually TiddlyWiki will use most recent jquery (which
is what TiddlySpace uses). We don't know, however, when this might
happen.
Update tests for #1069

Need to assert correct path to jquery.
Update total tiddler counts in tests.