Redistribution of GTK DLLs

[Chris Angelico <rosuav gmail com>]

I have a Pike GTK app that works on Windows and Linux (and
theoretically other platforms but I haven't tested it). The Windows
version of Pike distributes GTK DLLs for 2.12.11, which has some flaws
compared to 2.24.10 which I use elsewhere. So it would be convenient
for my users if I could have a simple command inside my app that goes
and fetches eighteen files (including Pango, Cairo, etc) and deploys
them to the correct location.

And therein is a licensing problem. GTK is licensed LGPL, but my app
is under the freer MIT license. So the question is: Am I making a
derivative/combined work by making an installer that fetches GTK DLLs?

I don't want to have to mess with the licensing of my project (putting
some of it under the (L)GPL) for the sake of a convenience feature,
but on the flip side, there's no point listing lengthy instructions
saying "go download this, extract this, put this this this and this in
here, then restart the program" if I can say "enter this one-word
command".

What's the rule on distributing DLLs with non-GPL software? The GPL
FAQ has a lot, but not really what I'm after.

Thanks!

ChrisA