add support for LZMA-enabled artifacts

[dicej]

No description provided.

[sgoings]

I'd like to use something other than curl to grab those files... maybe: https://github.com/michel-kraemer/gradle-download-task?

Also the failure looks like we need to take a look at how we're handling the win32/win64 artifacts/dependencies in the build.gradle. Oops! Looks like you fixed it.

[dicej]

The latest failure is a spurious failure of the Trace test, which we've seen before (and which used to go unnoticed back before #416 got fixed). It seems to fail maybe 1% of the time. I'll enter a new issue for that, but I'm sure it's not a regression related to this change.

[joshuawarner32]

Sorry, I didn't notice this had just been sitting around. @sgoings - can you force-push something to this branch to trigger the build again, just for my own comfort? This'll do it nicely: git checkout sgoings; git commit --amend --no-edit; git push -f. FWIW, I spent tried to reproduce the trace failure both on my mac host, and a linux VM, to no avail (I left Joel's script in #429 running for a couple hours).

[joshuawarner32]

Sorry, I didn't notice this hanging out. My bad!