#21 Stale links in documentation

[Ted Williams]

Some links in the latest version of ais/docs/onlinedocs/AStartup.html are stale.

Recreate: Open AStartup.html in a browser. Navigate to Assigning with Setq. Click on the link named String Object Reference Guide. Note that the file  ais/docs/onlinedocs/axstring.htm cannot be found. There are several stale links scattered about.