implement some stuff to make exaple SDL app run

NOTE: the main addition in this commit is WIP support for apps which
render on an EGL surface obtained using ANativeWindow_fromSurface

currently, this EGL surface is obtained by creating a 700x700 pixel
window with GLFW (the 700x700 size is hardcoded in several places)
and only Wayland is supported

ideally, we'd want to use a wayland subsurface to position the EGL
surface above the Surface widget it's associated with (and do
whatever for X11)

src/libandroid/sensor.c

@@ -0,0 +1,155 @@
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <aio.h>
+
+struct ASensorManager {
+	int dummy;
+};
+
+struct ASensorEventQueue;
+struct ASensorList;
+struct ASensor;
+struct ALooper;
+struct AHardwareBuffer;
+struct ASensorEvent;
+
+typedef void * ALooper_callbackFunc;
+
+struct ASensorManager a_sensor_manager;
+
+struct ASensorManager* ASensorManager_getInstance()
+{
+	return &a_sensor_manager;
+}
+
+// --- sensor manager
+
+int ASensorManager_getSensorList(struct ASensorManager* manager, struct ASensorList* list)
+{
+	return 0; // the number of sensors - any sane app should see this and stop messing with sensors
+}
+
+int ASensorManager_destroyEventQueue(struct ASensorManager* manager, struct ASensorEventQueue* queue)
+{
+	return 0;
+}
+
+
+int ASensorManager_createSharedMemoryDirectChannel(struct ASensorManager* manager, int fd, size_t size)
+{
+	return 0;
+}
+
+
+int ASensorManager_createHardwareBufferDirectChannel(struct ASensorManager* manager, struct AHardwareBuffer const * buffer, size_t size)
+{
+	return 0;
+}
+
+
+void ASensorManager_destroyDirectChannel(struct ASensorManager* manager, int channelId)
+{
+	return;
+}
+
+
+int ASensorManager_configureDirectReport(struct ASensorManager* manager, struct ASensor const* sensor, int channelId, int rate)
+{
+	return 0;
+}
+
+// --- event queue
+
+struct ASensorEventQueue* ASensorManager_createEventQueue(struct ASensorManager* manager, struct  ALooper* looper, int ident, ALooper_callbackFunc callback, void* data)
+{
+	return NULL;
+}
+
+int ASensorEventQueue_registerSensor(struct ASensorEventQueue* queue, struct ASensor const* sensor, int32_t samplingPeriodUs, int64_t maxBatchReportLatencyUs)
+{
+	return 0;
+}
+
+
+int ASensorEventQueue_enableSensor(struct ASensorEventQueue* queue, struct ASensor const* sensor)
+{
+	return 0;
+}
+
+
+int ASensorEventQueue_disableSensor(struct ASensorEventQueue* queue, struct ASensor const* sensor)
+{
+	return 0;
+}
+
+
+int ASensorEventQueue_setEventRate(struct ASensorEventQueue* queue, struct ASensor const* sensor, int32_t usec)
+{
+	return 0;
+}
+
+
+int ASensorEventQueue_hasEvents(struct ASensorEventQueue* queue)
+{
+	return 0;
+}
+
+
+ssize_t ASensorEventQueue_getEvents(struct ASensorEventQueue* queue, struct ASensorEvent* events, size_t count)
+{
+	return 0;
+}
+
+// --- sensor
+
+const char* ASensor_getName(struct ASensor const* sensor)
+{
+	return "FIXME-ASensor_getName";
+}
+
+const char* ASensor_getVendor(struct ASensor const* sensor)
+{
+	return "FIXME-ASensor_getVendor";
+}
+
+int ASensor_getType(struct ASensor const* sensor)
+{
+	return 0;
+}
+float ASensor_getResolution(struct ASensor const* sensor)
+{
+	return 1;
+}
+int ASensor_getMinDelay(struct ASensor const* sensor)
+{
+	return 0;
+}
+int ASensor_getFifoMaxEventCount(struct ASensor const* sensor)
+{
+	return 0;
+}
+int ASensor_getFifoReservedEventCount(struct ASensor const* sensor)
+{
+	return 0;
+}
+const char* ASensor_getStringType(struct ASensor const* sensor)
+{
+	return "FIXME-ASensor_getStringType";
+}
+int ASensor_getReportingMode(struct ASensor const* sensor)
+{
+	return 0;
+}
+bool ASensor_isWakeUpSensor(struct ASensor const* sensor)
+{
+	return 0;
+}
+bool ASensor_isDirectChannelTypeSupported(struct ASensor const* sensor, int channelType)
+{
+	return 0;
+}
+int ASensor_getHighestDirectReportRateLevel(struct ASensor const* sensor)
+{
+	return 1;
+}