DWB bugs

[gwyn at BRL-VLD.ARPA]

From:      Doug Gwyn (VLD/VMB) <gwyn at BRL-VLD.ARPA>

Someone involved with the production of the Documenter's Workbench,
Release 1.0, did not know that there is a difference between a
function returning float and a function returning double.  This
error occurs in many of the source files.

Also, the "hc" and "ta" filters were broken because someone (same
turkey?) used 512-byte buffers to setbuf() instead of BUFSIZ.

Sure hope these things weren't BWK's fault..