Fix Makefile work with zsh

In Zsh type prints not only executable path:
$ type tweego
tweego is /usr/bin/tweego

These additional words break the Makefile

Fixes #794 and closes #796.

Makefile

@@ -2,11 +2,11 @@ MAKEFLAGS += -r
 export TWEEGO_PATH=devTools/tweeGo/storyFormats
 HASH := $(shell git rev-list -n 1 --abbrev-commit HEAD)
 COMMIT := $(shell git rev-parse --short HEAD)
-uname := $(shell uname -s)
-arch := $(shell uname -m)
-arch := $(shell if test $(arch) = x86_64 -o $(arch) = amd64; then echo 64; else echo 32; fi)
-TWEEGO := $(shell if type tweego; then echo tweego; else echo 1; fi)
-ifeq ($(TWEEGO),1)
+TWEEGO := $(shell command -v tweego 2>/dev/null)
+ifndef TWEEGO
+	uname := $(shell uname -s)
+	arch := $(shell uname -m)
+	arch := $(shell if test $(arch) = x86_64 -o $(arch) = amd64; then echo 64; else echo 32; fi)
 	ifeq ($(uname),Linux)
 		ifeq ($(arch),64)
 			TWEEGO := devTools/tweeGo/tweego_nix64