- send errors to stderr
- send help to stdout
- add image size to webpmux -info output and send to stdout
- correct webpmux exit values
Change-Id: Ifd8e8493aab33a82765f7b7903cef345d96da9ae
escape '-'s
use consistent section names
webpmux.1:
document -loop
create subsections for each OPTION group
Change-Id: If41dc24d80e4a662024e82697d8d2cc4e194a35d