split rust.bbclass into rust & cargo classes

recipes-example/rust-hello-world/rust-hello-world_git.bb

@@ -1,4 +1,4 @@
-inherit rust
+inherit cargo
 
 SRC_URI = "git://github.com/jmesmon/rust-hello-world.git;protocol=https"
 SRCREV="e0fa23f1a3cb1eb1407165bd2fc36d2f6e6ad728"
@@ -10,20 +10,6 @@ LICENSE = "MIT | Apache-2.0"
 
 # FIXME: we really depend on cargo-native, but avoid it for now as building it
 # is more painful than it should be
-DEPENDS = "cargo-native"
+#DEPENDS = "cargo-native"
 
 S = "${WORKDIR}/git"
-B = "${S}"
-
-do_compile () {
-	oe_cargo_build
-}
-
-do_install () {
-	install -d "${D}${bindir}"
-	for tgt in "${B}/target/${HOST_SYS}/release/"*; do
-		if [ -f "$tgt" ] && [ -x "$tgt" ]; then
-			install -m755 "$tgt" "${D}${bindir}"
-		fi
-	done
-}