sokol_log: silence non-error output by default, don't print extra newlines

users don't know what these messages mean, it's useless output.
the extra newlines break the formatting style of other logging.
instead, disable output for higher log levels by default,
based on our own runtime debug settings.
we might always compile in the messages for convenience as well,
not sure why sokol chooses not to.

Author: qwx9

lib/sokol_log.h

@@ -248,9 +248,14 @@ EM_JS(void, slog_js_log, (uint32_t level, const char* c_str), {
 })
 #endif
 
+extern int debug;
+
 SOKOL_API_IMPL void slog_func(const char* tag, uint32_t log_level, uint32_t log_item, const char* message, uint32_t line_nr, const char* filename, void* user_data) {
     _SOKOL_UNUSED(user_data);
 
+	if (debug == 0 && log_level > 1)
+		return;
+
     const char* log_level_str;
     switch (log_level) {
         case 0: log_level_str = "panic"; break;
@@ -301,7 +306,7 @@ SOKOL_API_IMPL void slog_func(const char* tag, uint32_t log_level, uint32_t log_
         str = _slog_append("\n\t", str, end);
         str = _slog_append(message, str, end);
     }
-    str = _slog_append("\n\n", str, end);
+    str = _slog_append("\n", str, end);
     if (0 == log_level) {
         str = _slog_append("ABORTING because of [panic]\n", str, end);
         (void)str;