debug output

[David Relson]

Greetings,

Presently debug output in bogofilter, bogolexer, and bogoutil is controlled 
by a group of DEBUG_name macros.  This is a good thing as debugging output 
for various portions of the programs can be turned on by command line switches.

What is _not_ good is that some program sections print their debugging 
output to stdout and some print to stderr.  I have added a new variable 
"FILE *dbgout" to provide a uniform destination for debug output.  It is 
initialized during program startup.

Having a single variable like this makes it easy for a developer to change 
the destination of the output from stderr to stdout, if so desired.

David