[AD] const correctness

[Peter Wang <tjaden@xxxxxxxxxx>]

Attached is a patch to add some const-ness to user visible parts of
the library.  I don't think it's complete, but it's a start.

Before I forget, the library is missing `usnprintf' and `uvsnprintf'
functions. (I'm trying to be security conscious :-)

PS. I forgot to fix `set_window_title' before making the diff.

Peter
-- 
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Even a stopped clock gives the right time twice a day.

Attachment: alconst.diff.gz
Description: GNU Zip compressed data