Improve wording in debug player dialog

[citizenmatt]

If a player is a development build, but has script debugging disabled, it is listed as something like:

AndroidPlayer(Whatever@192.168.1.1) (Debugging disabled) 192.168.1.1:56767

We should change "(Debugging disabled)" to "(Script debugging disabled)" to reflect the option in Unity's Build Settings dialog. If possible, we should also add a tooltip to state something like:

This player is a development build but does not have script debugging enabled. Please check the Script Debugging option in Build Settings in Unity

[citizenmatt]

Also add some help text to state that it will show devices on the same network, but not connected via USB.