Template:Citation/make link

<!-- Code notes (here so that people /read/ it) 1. Parameter #2 is always nonempty when called from. 2. It's up to to stop italicized "'foo' & 'bar'" from becoming "foo' & 'bar". Citation/core does this by having a      at both beginning and end of the call to this template. Since this is only needed once, it's more efficient to do it in than here. -