Properly format multiline logs

As a side effect, colouring on Windows should now work
regardless of version

contrib/epee/src/mlog.cpp

@@ -109,7 +109,7 @@ static const char *get_default_categories(int level)
       categories = "*:DEBUG";
       break;
     case 3:
-      categories = "*:TRACE";
+      categories = "*:TRACE,*.dump:DEBUG";
       break;
     case 4:
       categories = "*:TRACE";
@@ -472,4 +472,40 @@ void reset_console_color() {
 
 }
 
+static void mlog(el::Level level, const char *category, const char *format, va_list ap)
+{
+  int size = 0;
+  char *p = NULL;
+  va_list apc;
+
+  /* Determine required size */
+  va_copy(apc, ap);
+  size = vsnprintf(p, size, format, apc);
+  va_end(apc);
+  if (size < 0)
+    return;
+
+  size++;             /* For '\0' */
+  p = (char*)malloc(size);
+  if (p == NULL)
+    return;
+
+  size = vsnprintf(p, size, format, ap);
+  if (size < 0)
+  {
+    free(p);
+    return;
+  }
+
+  MCLOG(level, category, el::Color::Default, p);
+  free(p);
+}
+
+void mfatal(const char *category, const char *fmt, ...) { va_list ap; va_start(ap, fmt); mlog(el::Level::Fatal, category, fmt, ap); va_end(ap); }
+void merror(const char *category, const char *fmt, ...) { va_list ap; va_start(ap, fmt); mlog(el::Level::Error, category, fmt, ap); va_end(ap); }
+void mwarning(const char *category, const char *fmt, ...) { va_list ap; va_start(ap, fmt); mlog(el::Level::Warning, category, fmt, ap); va_end(ap); }
+void minfo(const char *category, const char *fmt, ...) { va_list ap; va_start(ap, fmt); mlog(el::Level::Info, category, fmt, ap); va_end(ap); }
+void mdebug(const char *category, const char *fmt, ...) { va_list ap; va_start(ap, fmt); mlog(el::Level::Debug, category, fmt, ap); va_end(ap); }
+void mtrace(const char *category, const char *fmt, ...) { va_list ap; va_start(ap, fmt); mlog(el::Level::Trace, category, fmt, ap); va_end(ap); }
+
 #endif //_MLOG_H_