Stop encouraging Acrobat as the preferred PDF reader

[jdreed]

(Before anyone freaks out, please note the words "encouraging" and "preferred", not "providing" and "only").

In the Pharos world, Acrobat, with it's stupid hybrid-CUPS-LPR environment, still spools jobs from /tmp, so your stuff ends up on the Pharos display as "Acro23987fa", which is not heplful. Additionally, it seems to have issues doing the right thing with duplex printing sometimes. So while it can still be used, we should stop encouraging it in our docs, and should consider replacing the Firefox plugin with something else (is there something else?)

[jdreed]

It's not at all clear to me this is the right answer anymore.