Merge pull request #18 from mrichie/master

Add BC.Bluetooth.CloseBluetooth Interface in Android.
Change the callback storage location

Change the callback storage location ,from the NSUserDefaults to the
object.  That can simultaneously for multiple calls his object service.
Save notification callbackId
Update README.md
add base64 write data type.
read interface just return the ArrayBuffer type data.
Merge pull request #1 from bcsphere/master

merge