combine what was previously achieved by the separate binaries
villas-fpga-xbar-select and villas-fpga-cat into a single new
binary villas-fpga-ctl. Here we can select crossbar connections
via command line parameters. To avoid regression there are shell
scripts providing the old functionalities directly.
Currently the villas-fpga-pipe functionality is not supported,
because we still need to implement stdin input and routing that
to the fpga.
Signed-off-by: Niklas Eiling <niklas.eiling@eonerc.rwth-aachen.de>