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. 

Even with these installed, Cbc package still prefers to build it's own copy. There is a slight difference in the versions (2.8.7 installed by apt-get whereas 2.8.12 needed for the package). I think we should install the same packages as mentioned in the bindeps apt-get provider. In this case there are none.