Avoid compiler warnings with MinGW runtime 3.22.2

* main.c:
* job.c: Include strings.h, to get the prototypes of strcasecmp
and strncasecmp with latest MinGW runtime versions.
* config.h.W32.template (HAVE_STRINGS_H): Define.
diff --git a/config.h.W32.template b/config.h.W32.template
index d72e79a..450be4f 100644
--- a/config.h.W32.template
+++ b/config.h.W32.template
@@ -268,7 +268,7 @@
 #define HAVE_STRICMP 1
 
 /* Define to 1 if you have the <strings.h> header file. */
-/* #define HAVE_STRINGS_H 1 */
+#define HAVE_STRINGS_H 1
 
 /* Define to 1 if you have the <string.h> header file. */
 #define HAVE_STRING_H 1
diff --git a/job.c b/job.c
index f3a9fdb..4da0244 100644
--- a/job.c
+++ b/job.c
@@ -29,6 +29,7 @@
 
 /* Default shell to use.  */
 #ifdef WINDOWS32
+#include <strings.h>	/* for strcasecmp, strncasecmp */
 #include <windows.h>
 
 const char *default_shell = "sh.exe";
diff --git a/main.c b/main.c
index fa8045f..a1703ed 100644
--- a/main.c
+++ b/main.c
@@ -33,6 +33,7 @@
 #ifdef WINDOWS32
 # include <windows.h>
 # include <io.h>
+# include <strings.h>	/* for strcasecmp */
 # include "pathstuff.h"
 # include "sub_proc.h"
 # include "w32err.h"