go spec: added imaginary literal to semicolon rules (was missing)
go spec: added imaginary literal to semicolon rules (was missing)

- also added links to the respective sections
- reformatted section for better (source html) readability
- added missing closing </li>'s in many places

R=r
CC=golang-dev
http://codereview.appspot.com/1220041

tav/go,tav/go,tav/go,tav/go,tav/go,tav/go,tav/go