fix issues in example scripts

- in case cd fails don't continue (don't write in previous directory).
- post-receive: quote $(pwd) in case it has spaces.

found by shellcheck tool.

example_create.sh

@@ -30,7 +30,7 @@ for dir in "${reposdir}/"*/; do
 	printf "%s... " "${d}"
 
 	mkdir -p "${curdir}/${d}"
-	cd "${curdir}/${d}"
+	cd "${curdir}/${d}" || continue
 	stagit -c ".cache" "${reposdir}/${r}"
 
 	# symlinks