* companion: added Datastore methods: getStorageUsedKb(), getStorageTotalKb()

* companion: CMD_GET_BATTERY now changed to CMD_GET_BATT_AND_STORAGE

examples/companion_radio/DataStore.h

@@ -39,4 +39,6 @@ public:
   bool putBlobByKey(const uint8_t key[], int key_len, const uint8_t src_buf[], uint8_t len);
   File openRead(const char* filename);
   bool removeFile(const char* filename);
+  uint32_t getStorageUsedKb() const;
+  uint32_t getStorageTotalKb() const;
 };