Micro will now also search for a program called micro-clip for handling
the clipboard. This allows the user to make a program called micro-clip
that micro will call out to for performing copy/paste. For copy it will
be called with `micro-clip -i <reg>` and the text will be provided on
stdin. For paste it will be called with `micro-clip -o <reg>` and micro
expects the text to be provided on stdout.
