Include dependencies version

On --version, also print the dependencies version scrcpy has been
compiled against.

app/src/main.c

@@ -4,6 +4,7 @@
 #include <unistd.h>
 #include <libavformat/avformat.h>
 #include <SDL2/SDL.h>
+#include <SDL2/SDL_net.h>
 
 #include "config.h"
 
@@ -87,6 +88,17 @@ static void usage(const char *arg0) {
         DEFAULT_LOCAL_PORT);
 }
 
+static void print_version(void) {
+    fprintf(stderr, "scrcpy v%s\n\n", SCRCPY_VERSION);
+
+    fprintf(stderr, "dependencies:\n");
+    fprintf(stderr, " - SDL %d.%d.%d\n", SDL_MAJOR_VERSION, SDL_MINOR_VERSION, SDL_PATCHLEVEL);
+    fprintf(stderr, " - SDL_net %d.%d.%d\n", SDL_NET_MAJOR_VERSION, SDL_NET_MINOR_VERSION, SDL_NET_PATCHLEVEL);
+    fprintf(stderr, " - libavcodec %d.%d.%d\n", LIBAVCODEC_VERSION_MAJOR, LIBAVCODEC_VERSION_MINOR, LIBAVCODEC_VERSION_MICRO);
+    fprintf(stderr, " - libavformat %d.%d.%d\n", LIBAVFORMAT_VERSION_MAJOR, LIBAVFORMAT_VERSION_MINOR, LIBAVFORMAT_VERSION_MICRO);
+    fprintf(stderr, " - libavutil %d.%d.%d\n", LIBAVUTIL_VERSION_MAJOR, LIBAVUTIL_VERSION_MINOR, LIBAVUTIL_VERSION_MICRO);
+}
+
 static int parse_args(struct args *args, int argc, char *argv[]) {
     static const struct option long_options[] = {
         {"help",     no_argument,       NULL, 'h'},
@@ -209,7 +221,7 @@ int main(int argc, char *argv[]) {
     }
 
     if (args.version) {
-        fprintf(stderr, "scrcpy v%s\n", SCRCPY_VERSION);
+        print_version();
         return 0;
     }