Add a master Makefile with docker dev env support and address compiler warning that showed up in the Docker dev env

Makefile

@@ -0,0 +1,46 @@
+DEVENV=devenv$(shell pwd | sed 's/\//-/g')
+ifeq ($(shell docker inspect --format="{{.State.Status}}" ${DEVENV} 2>&1),running)
+	ENV_RUN=docker exec --user $(shell id -u ${USER}) ${DEVENV}
+endif
+
+make:
+	${ENV_RUN} make -j -C build
+preinstall:
+	${ENV_RUN} make -j -C build ARGS="preinstall"
+install:
+	${ENV_RUN} make -j -C build ARGS="install"
+clean:
+	${ENV_RUN} make -j -C build ARGS="clean"
+purge:
+	${ENV_RUN} rm -rf $(find build -mindepth 1 -maxdepth 1 -type d)
+test:
+	${ENV_RUN} make -j -C build ARGS="test"
+run: make
+	./build/current/src/wombat/wombat -debug
+debug: make
+	gdb ./build/current/src/wombat/wombat
+devenv:
+	docker pull wombatant/devenv
+	docker run -d -v $(shell pwd):/usr/src/project \
+		-e LOCAL_USER_ID=$(shell id -u ${USER}) \
+		--name ${DEVENV} -t wombatant/devenv bash
+devenv-destroy:
+	docker rm -f ${DEVENV}
+
+native:
+	${ENV_RUN} rm -rf build/release
+	${ENV_RUN} ./scripts/setup_build
+	${ENV_RUN} rm -f build/current
+	${ENV_RUN} ln -s release build/current
+
+native_debug:
+	${ENV_RUN} rm -rf build/debug
+	${ENV_RUN} ./scripts/setup_build_debug
+	${ENV_RUN} rm -f build/current
+	${ENV_RUN} ln -s debug build/current
+
+gba:
+	${ENV_RUN} rm -rf build/gba
+	${ENV_RUN} ./scripts/setup_build_gba
+	${ENV_RUN} rm -f build/current
+	${ENV_RUN} ln -s gba build/current