- update API for connectable
- update API for connectable

pi19404/arduino-BLEPeripheral,sandeepmistry/arduino-BLEPeripheral,femtoduino/arduino-BLEPeripheral,possan/arduino-BLEPeripheral,possan/arduino-BLEPeripheral,pi19404/arduino-BLEPeripheral,sandeepmistry/arduino-BLEPeripheral,femtoduino/arduino-BLEPeripheral,sandeepmistry/arduino-BLEPeripheral