. Integrate fdc.h into fd.c, with the removal of ft(4) there's no longer
a reason to scatter things across two files.
. Sanitize comments. Convert them into the style(9)-recommended
multi-line form, make them sentences where apprpriate, etc.
. Declare all functions on top, and declare them in the order they
appear in the file. This order is totally chaotic, but Bruce
convinced me that reordering the file wouldn't make it better either.
. Kill a `possibly uninitialized' warning (only seen with -O2) in
fd_read_status().
. Make the comments at return (0|1) statements in fdstate() consistent.
. Nuke a ``keep the compiler happy'' dummy return at the end of fdstate(),
gcc is smart enough to detect that it would never be reached anyway.