#12 Add support for images

[Bill Thies]

A user is requesting that we include images in the
results, because (for example) mathematical texts are
empty without the equations. This functionality seems
to be mostly in place, except for a way to indicate the
preference for images on the client side.

However, when I manually toggle the Images tag in the
TEK query email from "false" to "true", the Server hangs
upon doing the first download. It needs to be manually
terminated and restarted. I haven't investigated this --
we should figure out what's going on.