This patch does the following:

• replaces FreeBSD with entity
• adds acronym tags for instances of PPP that refer to the protocol, the instances that refer to the app still need to be fixed
• comments out "26.5.1. Using PPPoA with the Alcatel SpeedTouch USB" as the port it relies on has been broken for 4 years
• fixes internal links

This will be followed by a white space fix.