Remove link to ImgLib2 Fiji wiki page

The site imglib2.net redirects to that same page anyway.
And imglib2.net is a more future-proof URL in any case.
Use "See also" boxes where relevant
Rework out-of-date FARSIGHT documentation

The code formerly known as BF-ITK is now integrated directly into ITK,
and as such much of this information has been simplified. The
Bio-Formats ITK page has most of the informational meat; the FARSIGHT
page merely needs to mention that it uses ITK to harness Bio-Formats.