Build sgdisk command line tool for use on Android devices.  The
command line parsing is currently written using popt, which has been
deprecated for some time, and is replaced by GNOME's glib option
parser.

Instead of pulling in either of those dependencies, this change
adds a stub that implements just enough of popt to get things
working.

Change-Id: I619f8da2e413893b4ea015a5d9e48d42637e25c8