setuptools.bbclass: import from OE

Signed-off-by: Koen Kooi <koen@dominion.thruhere.net>

classes/setuptools.bbclass

@@ -0,0 +1,8 @@
+inherit distutils
+
+DEPENDS += "python-setuptools-native"
+
+DISTUTILS_INSTALL_ARGS = "--root=${D} \
+    --single-version-externally-managed \
+    --prefix=${prefix} \
+    --install-data=${datadir}"