Added ability to menu to copy current location to the clipboard.

[alaskalinuxuser]

In reference to issue #95 I have added the ability to copy the current location to your clipboard, which can be pasted into any other application.

A few notes: I used the text views to pull the data for the clipboard because if you do not have a position, then you will get - - instead of an error or nothing. And it will copy the location in the method specified in settings menu. If you choose MGRS, Decimal, Dec min, DDMMSS, it still copies as you set in your settings preferences.

I have tested this on a Samsung Galaxy S4, Android 7.1.2, using MGRS, Decimal, Decimal Minutes, and Decimal Minutes Seconds. All copied without error. I also tested if you have no location, still copies to clipboard without error, just as " - - ".