Add toolchain and submodules for gateware + firmware development

.gitmodules

+[submodule "submodules/wr-cores"]
+	path = submodules/wr-cores
+	url = git://ohwr.org/hdl-core-lib/wr-cores.git
+	branch = cute-wr
+[submodule "submodules/wrpc-sw"]
+	path = submodules/wrpc-sw
+	url = git://ohwr.org/hdl-core-lib/wr-cores/wrpc-sw.git
+[submodule "submodules/hdl-make"]
+	path = submodules/hdl-make
+	url = git://ohwr.org/misc/hdl-make.git

README

-
-cute-wr demo system using siTCP.

hdl-make @ aabe6c84

+Subproject commit aabe6c840ed4d8414dd62bb67781e10672184103

wr-cores @ 07a5e898

+Subproject commit 07a5e8985794ac278e0939b9ec527a21bc9a8514

wrpc-sw @ 1c061f05

+Subproject commit 1c061f05778de9af7044d6fcb91c869cdf311508