The file I uploaded to ohwr (wrs3-gw-v3.0-20120801.tar.gz) is not
expected to be renamed or overwritten in the future, so this commit
and the following ones will always build properly.

We had this problem with the previous file name being replaced, so
older commits didn't build any more for lack of the required gateware
file or md5sum errors.

Signed-off-by: Federico Vaga <federico.vaga@gmail.com>

Signed-off-by: Federico Vaga <federico.vaga@gmail.com>

This patch also update the relative documentation
Signed-off-by: Federico Vaga <federico.vaga@gmail.com>

build scripts: wrs_build_gateware: use self-compiled RT CPU from rt/ or pre-compiled binary from binaries/. Updated download info for gateware

Conflicts:

	modules/wrsw_rtu/rtu_wishbone_slave.vhd