Endianness should be flipped at set AND get

[nicoinn]

Endianness of major, minor and manufacturerID are swapped upon calling the corresponding set method, but they are not swapped back when calling the get.

Example code to demonstrate the issue

Beacon.setMajor(0xABCD);
Serial.printf("TEST: 0x%02x -- Should be 0x%02x\n",oBeacon.getMajor(),0xABCD);

Will print
TEST: 0xcdab -- Should be 0xabcd

This patches re-establishes the original endianness while called the get method.