Merging completely revised version into master

Created by: robertbruntz

Robert Bruntz has been re-working the entire script over the last ~1.5 years, setting the script up to install different components on different machines (segments, segments-backup, segments-web, segments-dev). The code is also broken into separate sections, each of which can be run or skipped based on user-set variables. There is now an introduction and instructions at the beginning, comments throughout, and a to-do list at the end.