Installation scripts for daemon mode on Ubuntu using Upstart

This work is based upon upstream work in bitcoin core on the master branch and in some PRs.
The "Cherry Pick" commit is here: https://github.com/msgilligan/mastercore/commit/55a97b93223919171195fb11c11281c9cdb0be3e

All files (both the "cherry pick" files and the ones that I've added are in the `contrib` subdirectory.