* windres.c: add verbose option

* windres.c: add verbose option
(main): process verbose option
* resrc.c (look_for_default): new.  Look for the default
preprocessor in a given location.
(read_rc_file): for foo/bar-windres, look for foo/bar-gcc,
foo/gcc (in case of foo/windres), and then gcc (the old default).