rename setup scripts starting with underscore so Middleman will ignore them

On branch master
Changes to be committed:

	renamed:    setup_part1_root.sh -> _setup1.sh
	renamed:    setup_part2_nonroot.sh -> _setup2.sh
centralize duplicate code into function library

On branch master
Changes to be committed:

	modified:   .gitignore
	modified:   README.md
	modified:   _setup1.sh
	modified:   _setup2.sh
add library file