[Agda] Abbreviation mode

[Robin Green]

Two points about abbrev-mode:

The instructions on the wiki at
http://wiki.portal.chalmers.se/agda/agda.php?n=Main.Abbreviation
don't work - the ' and " characters have been turned into so-called
"Smart Quotes", which confuses emacs.

Also, the "Agda2 Mode Abbrevs Use Defaults:" option should probably
default to No.

How does one use the default abbreviations if that option is turned
off, by the way?

-- 
Robin