include: add missing includes

lib/pager.c: signal.h ... raise(3p)
lib/sysfs.c: libgen.h ... basename(3p)
lib/exec_shell.c: libgen.h ... basename(3p)

Signed-off-by: Ruediger Meier <ruediger.meier@ga-group.nl>

lib/exec_shell.c

@@ -20,6 +20,7 @@
 #include <string.h>
 #include <unistd.h>
 #include <sys/types.h>
+#include <libgen.h>
 
 #include "nls.h"
 #include "c.h"

lib/pager.c

@@ -12,6 +12,7 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include <signal.h>
 
 #include "c.h"
 #include "xalloc.h"

lib/sysfs.c

@@ -5,6 +5,7 @@
  * Written by Karel Zak <kzak@redhat.com>
  */
 #include <ctype.h>
+#include <libgen.h>
 
 #include "c.h"
 #include "at.h"