HWIU provides more information about the gateware build and in the same time can
read debug registers and drive chipscope mux in the same way HWDU does it. For
now one of them can be selected with generic, but once I test HWIU I'll remove
HWDU module.

Conflicts:
	Manifest.py
	ip_cores/general-cores
	modules/wrsw_nic/nic_tx_fsm.vhd
	modules/wrsw_nic/nic_wbgen2_pkg.vhd
	modules/wrsw_nic/nic_wishbone_slave.vhd
	modules/wrsw_nic/wrsw_nic.vhd
	modules/wrsw_nic/xwrsw_nic.vhd
	top/bare_top/scb_top_bare.vhd
	top/bare_top/wrsw_components_pkg.vhd
	top/bare_top/wrsw_top_pkg.vhd
	top/scb_18ports/scb_top_synthesis.vhd

- removed declarations of unused signals
- reduced padding_size to bits needed for padding possible runt Ethernet
  frames
- simplified signal assignments and conditions in FSM (e.g. no need to
  check if needs_padding = 1 and padding_size /= 0, because when former
  is true, the latter is always true too)
- moved assignment of outputs validated with other outputs outside FSM
  to simplify the logic (fake rtu decision)

Instead of old fabtic converted to Pipelined WB using ep_rx_wb_master
module from endpoint_private_pkg