spm

Revert "Write error messages to stderr only"

This reverts commit 2ce3615e98ebbf6897d83064a29a579dc3bc9b2c.

>&1 means "redirect printf's output to stdout", so 2c361 actually
broke the very functionality it was supposed to implement/add.

I don't know why I even committed this in the first place, but now it's
fixed again: Normal output from `list' and `show' go to stdout,
diagnostic messages appear on stderr making spm easier to handle/work
with.

diff --git a/spm.sh b/spm.sh
@@ -31,7 +31,7 @@ fi
 ## Helper
 
 die() {
-	printf '%s\n' "${1}" >&1
+	printf '%s\n' "${1}" 1>&2
 	exit 1
 }