Implement @MAIN, @/path/name -e selectors, make former default for now

- the default might become "*" in future, but keep things more or less
  the same as they always were for now
diff --git a/proc.c b/proc.c
index 8fc4cae..8c42c4a 100644
--- a/proc.c
+++ b/proc.c
@@ -500,8 +500,8 @@
 	assert(lib->next == NULL);
 	lib->next = proc->libraries;
 	proc->libraries = lib;
-	fprintf(stderr, "=== Added library %s@%p to %d:\n",
-		lib->name, lib->base, proc->pid);
+	fprintf(stderr, "=== Added library %s@%p (%s) to %d:\n",
+		lib->soname, lib->base, lib->pathname, proc->pid);
 
 	if (!filter_matches_library(options.filter, lib))
 		return;