pre-build libraries for Julia packages and create default git config

Build and install native dependencies of bundled Julia packages in base image. Reduces build time and space requirement for Julia packages (Dockerfile v13).

Also generating a default git config for users on first login. 

`/usr/local` should be fine, since the coinblas and coinlapack names shouldn't overwrite anything. As long as you follow the static-linking to blas and lapack steps that the package does, I think it should work. Not sure about the `ldconfig` stuff though. Would be good to `Pkg.test("Ipopt")` to make sure, both before and after doing blas-related things in Julia (maybe like running the blas tests). I could be wrong though, if `Pkg.test("Ipopt")` is working now then maybe the Ubuntu package will be fine.