Add Slic3r-0.9.10b and improved client discovery of slicers

I believe I correctly added Slic3r 0.9.10b. I did not remove Slic3r 0.9.8, which probably should be done, but can be done after this if need be. I'm going to re-image my card and test it today as well, and I'll update this once that is complete.

I also modified ginsu so it tries to create a Slic3r for whatever engine it is given. I then call "getSlicerPath" (which might be better called in the constructor) which checks if that engine exists on the client, and if it does exist, that it exists for that client type.

Boost-Geometry-Utils was updated to 0.14 as > 0.12 was needed for slic3r. I also changed the way that it checked out 0.9.10b because the previous I believe checks out a tag, and that wasn't working correctly. It's okay because it'll have to be updated next Slic3r anyway.