testing and benchmarking functions of opencv

- Benchmark measurement tool added
- Tested a bunch of function
	- TODO: See why some function don't give stack memory back!

esp32/examples/esp_opencv_tests/main/system.hpp

@@ -0,0 +1,20 @@
+//
+// Created by joachim on 24.03.20.
+//
+
+#ifndef SYSTEM_HPP
+#define SYSTEM_HPP
+
+// Initialize the SPIFFS
+esp_err_t init_spiffs();
+
+// Display cpu and memory info
+void disp_mem_infos();
+
+// Holds the task for a given amount of msec
+void wait_msec(uint16_t v);
+
+// Holds the task for a full second
+void wait_sec(uint16_t v);
+
+#endif //SYSTEM_HPP