Add alternative variant for the display of __FILE__ (__path_file__)

- __path_file__ includes the relevant parts of source path


Origin commit data
------------------
Commit: 92a88906a5
Author: Michael Liebmann <tuxcode.bbg@gmail.com>
Date: 2016-09-04 (Sun, 04 Sep 2016)

configure.ac

@@ -228,8 +228,10 @@ fi
 # hack to define a short filename also for out-of-tree build
 if test `dirname $0` = `pwd`; then
 	HWLIB_CFLAGS="$HWLIB_CFLAGS "'-D__file__=__FILE__'
+	HWLIB_CFLAGS="$HWLIB_CFLAGS "'-D__path_file__=__FILE__'
 else
 	HWLIB_CFLAGS="$HWLIB_CFLAGS "'-D__file__="\"$(subst $(srcdir)/,,$(abspath $<))\""'
+	HWLIB_CFLAGS="$HWLIB_CFLAGS "'-D__path_file__="\"$(subst $(top_srcdir)/,,$(abspath $<))\""'
 fi
 #
 # Check for libtdservicedb - the new one - for testing only