From Ronnie Sahlberg: have a registration interface for tap listeners,

From Ronnie Sahlberg: have a registration interface for tap listeners,
and generate the table of stuff to register from tap source files, so
Tethereal doesn't need to know what tap listeners exist.

Get rid of "tap-xxx.h" files, as they're now empty.

Add "tethereal-tap-register.c" to the .cvsignore file, as it's a new
generated file.

Update "Makefile.nmake" to generate "tethereal-tap-register.c".

Clean up "Makefile.am" and "Makefile.nmake" a bit.

svn path=/trunk/; revision=6525