Switch to new download format and update package scripts

post_install.sh

@@ -1,7 +1,10 @@
-#!/bin/bash
+#!/bin/sh
 
-SHELL="/bin/zsh"
+SHELLS="/bin/zsh /usr/bin/zsh"
 
-if ! grep "${SHELL}" "$BPM_ROOT"/etc/shells; then
-  echo "${SHELL}" | tee -a "$BPM_ROOT"/etc/shells
-fi
+for _shell in $SHELLS; do
+  if ! grep -q "^${_shell}\$" /etc/shells; then
+    echo "Adding '$_shell' to /etc/shells..."
+    echo "$_shell" | tee -a /etc/shells 1>/dev/null
+  fi
+done