Add minification support to the composite bundler, and also solve the
problem of otherwise requiring multiple requests to be made by the
browser if multiple technology types are in use.
Fix test I broke on earlier commit.
Prevent the new js bundler from being used from the servlet at present,
so it's easier to run all tests and verify that everything is still
working.
Fix a bug that was introduced earlier when I previously 'squished one of
the easy TODOs'.