Fix a bunch of compiler warnings.

We need to ensure that libsigrokdecode.h is always the first #include,
otherwise some versions of Python will cause all kinds of compiler
warnings like these:

  CC       device.o
In file included from /usr/include/python3.2mu/Python.h:8:0,
                 from [...]/include/libsigrokdecode/libsigrokdecode.h:25,
                 from sigrok-cli.h:26,
                 from device.c:23:
/usr/include/python3.2mu/pyconfig.h:1182:0: warning: "_POSIX_C_SOURCE" redefined [enabled by default]
 #define _POSIX_C_SOURCE 200112L
 ^
In file included from /usr/include/limits.h:26:0,
                 from /usr/lib/gcc/x86_64-linux-gnu/4.8/include-fixed/limits.h:168,
                 from /usr/lib/gcc/x86_64-linux-gnu/4.8/include-fixed/syslimits.h:7,
                 from /usr/lib/gcc/x86_64-linux-gnu/4.8/include-fixed/limits.h:34,
                 from /usr/lib/x86_64-linux-gnu/glib-2.0/include/glibconfig.h:11,
                 from /usr/include/glib-2.0/glib/gtypes.h:34,
                 from /usr/include/glib-2.0/glib/galloca.h:34,
                 from /usr/include/glib-2.0/glib.h:32,
                 from device.c:21:
/usr/include/features.h:231:0: note: this is the location of the previous definition
 #  define _POSIX_C_SOURCE 200809L
 ^

Since sigrok-cli.h already #includes libsigrok.h and libsigrokdecode.h,
just ensure that the latter is always the first #include by _only_
including it in sigrok-cli.h and nowhere else.

anykey.c

@@ -17,6 +17,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include "sigrok-cli.h"
 #include <stdio.h>
 #ifdef _WIN32
 #include <windows.h>
@@ -26,8 +27,6 @@
 #include <unistd.h>
 #include <string.h>
 #include <glib.h>
-#include <libsigrok/libsigrok.h>
-#include "sigrok-cli.h"
 
 #ifdef _WIN32
 static HANDLE stdin_handle;

decode.c

@@ -17,13 +17,9 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include "sigrok-cli.h"
 #include "config.h"
 #include <glib.h>
-#include <libsigrok/libsigrok.h>
-#ifdef HAVE_SRD
-#include <libsigrokdecode/libsigrokdecode.h> /* First, so we avoid a _POSIX_C_SOURCE warning. */
-#endif
-#include "sigrok-cli.h"
 
 #ifdef HAVE_SRD
 static GHashTable *pd_ann_visible = NULL;

device.c

@@ -17,10 +17,9 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include "sigrok-cli.h"
 #include "config.h"
 #include <glib.h>
-#include <libsigrok/libsigrok.h>
-#include "sigrok-cli.h"
 
 extern struct sr_context *sr_ctx;
 extern gchar *opt_drv;

input.c

@@ -17,10 +17,9 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include "sigrok-cli.h"
 #include "config.h"
 #include <glib.h>
-#include <libsigrok/libsigrok.h>
-#include "sigrok-cli.h"
 
 extern gchar *opt_input_file;
 extern gchar *opt_input_format;

main.c

@@ -17,13 +17,9 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include "sigrok-cli.h"
 #include "config.h"
 #include <glib.h>
-#include <libsigrok/libsigrok.h>
-#ifdef HAVE_SRD
-#include <libsigrokdecode/libsigrokdecode.h> /* First, so we avoid a _POSIX_C_SOURCE warning. */
-#endif
-#include "sigrok-cli.h"
 
 struct sr_context *sr_ctx = NULL;
 #ifdef HAVE_SRD

parsers.c

@@ -17,13 +17,12 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include "sigrok-cli.h"
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdint.h>
 #include <string.h>
 #include <glib.h>
-#include <libsigrok/libsigrok.h>
-#include "sigrok-cli.h"
 
 static struct sr_probe *find_probe(GSList *probelist, const char *probename)
 {

session.c

@@ -17,14 +17,10 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include "sigrok-cli.h"
 #include "config.h"
 #include <glib.h>
 #include <glib/gstdio.h>
-#include <libsigrok/libsigrok.h>
-#ifdef HAVE_SRD
-#include <libsigrokdecode/libsigrokdecode.h> /* First, so we avoid a _POSIX_C_SOURCE warning. */
-#endif
-#include "sigrok-cli.h"
 
 static struct sr_output_format *output_format = NULL;
 static int default_output_format = FALSE;

show.c

@@ -17,13 +17,9 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include "sigrok-cli.h"
 #include "config.h"
 #include <glib.h>
-#include <libsigrok/libsigrok.h>
-#ifdef HAVE_SRD
-#include <libsigrokdecode/libsigrokdecode.h>
-#endif
-#include "sigrok-cli.h"
 
 extern gint opt_loglevel;
 extern gchar *opt_pds;

sigrok-cli.h

@@ -21,10 +21,11 @@
 #define SIGROK_CLI_SIGROK_CLI_H
 
 #include "config.h"
-#include <libsigrok/libsigrok.h>
 #ifdef HAVE_SRD
+/* First, so we avoid a _POSIX_C_SOURCE warning. */
 #include <libsigrokdecode/libsigrokdecode.h>
 #endif
+#include <libsigrok/libsigrok.h>
 
 #define DEFAULT_OUTPUT_FORMAT "bits:width=64"