Not trying to connect when Bluetooth is disabled.

[sharppaul]

Improved LogCat messages.
Caught NullPointerExceptions (occured when Bluetooth was disabled AND Android Location services was disabled)

Note: this change does require JAVA 7 or higher e.g. with this in build.gradle:

    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_7
        targetCompatibility JavaVersion.VERSION_1_7
    }

The reason for this is catching multiple distinct Exceptions in one catch block.