[patch] Autosave for version 2.0.5

[dl8dtl]

I've posted this patch quite some time ago on the old Yahoo! group, but never got
a response. We've been using it successfully here for a number of years now, and
it saved my back in at least a couple of times:

http://tech.groups.yahoo.com/group/qcad ... ssage/1838

The actual patch can be found here:

http://www.sax.de/~joerg/qcad-autosave.patch

Feel free to comment on this (including "that feature is available in the professional
version anyway" ;-).