Clean up path-setting (i) arrange hierarchically (ii) add some more links from GNU, Apple and Users (iii) word smithing (iv) advice from GNU.  This version without http links - to be added when I figure out how to avoid the spam filter
add http link
more http links
more http links
Flatten hierarchy one level
minor wordsmithing
Correct formatting
formatting
formatting
formatting
tweak launchd
minor correction