Elementary support for -x

- this is applied across libraries.  Syntax for the -x option is the same
  as for -e
- this fails on symbol aliases.  E.g. there are several symbols named like
  strlen in libc: strlen, __GI_strlen, and perhaps others.  This needs to
  be taken into account, and symbol aliases shouldn't be enabled if
  they were added under a different name already
diff --git a/options.h b/options.h
index 82b13c8..651d424 100644
--- a/options.h
+++ b/options.h
@@ -22,6 +22,7 @@
 	int bt_depth;	 /* how may levels of stack frames to show */
 #endif /* defined(HAVE_LIBUNWIND) */
 	struct filter *plt_filter;
+	struct filter *static_filter;
 	int hide_caller; /* Whether caller library should be hidden.  */
 };
 extern struct options_t options;
@@ -41,18 +42,8 @@
 	struct opt_F_t *next;
 };
 
-struct opt_x_t {
-	char *name;
-	int found;
-	unsigned long hash;
-	struct opt_x_t *next;
-};
-
 extern struct opt_p_t *opt_p;	/* attach to process with a given pid */
 
 extern struct opt_F_t *opt_F;	/* alternate configuration file(s) */
 
-extern struct opt_x_t *opt_x;	/* list of functions to break at */
-extern unsigned int opt_x_cnt;
-
 extern char **process_options(int argc, char **argv);