UI: Add popup warnings for connection failure

Also, check for null stream path/key in the RTMP output module.

libobs/obs-defs.h

@@ -30,5 +30,5 @@
 #define OBS_OUTPUT_BAD_PATH       -1
 #define OBS_OUTPUT_CONNECT_FAILED -2
 #define OBS_OUTPUT_INVALID_STREAM -3
-#define OBS_OUTPUT_FAIL           -4
+#define OBS_OUTPUT_ERROR          -4
 #define OBS_OUTPUT_DISCONNECTED   -5

libobs/obs-output.c

@@ -37,8 +37,10 @@ const char *obs_output_getdisplayname(const char *id, const char *locale)
 }
 
 static const char *output_signals[] = {
-	"void start(ptr output, int errorcode)",
-	"void stop(ptr output)",
+	"void start(ptr output)",
+	"void stop(ptr output, int code)",
+	"void reconnect(ptr output)",
+	"void reconnect_success(ptr output)",
 	NULL
 };
 
@@ -519,7 +521,7 @@ static inline void signal_start(struct obs_output *output)
 static inline void signal_stop(struct obs_output *output, int code)
 {
 	struct calldata params = {0};
-	calldata_setint(&params, "errorcode", code);
+	calldata_setint(&params, "code", code);
 	calldata_setptr(&params, "output", output);
 	signal_handler_signal(output->context.signals, "stop", &params);
 	calldata_free(&params);

libobs/util/base.h

@@ -28,6 +28,13 @@
 extern "C" {
 #endif
 
+#define STRINGIFY(x) #x
+#define STRINGIFY_(x) STRINGIFY(x)
+#define S__LINE__ STRINGIFY_(__LINE__)
+
+#define INT_CUR_LINE __LINE__
+#define FILE_LINE __FILE__ " (" S__LINE__ "): "
+
 enum {
 	/**
 	 * Use if there's a problem that can potentially affect the program,