Force correct permissions on Debian files

Somehow our build machine is set up subtly differently from the VM we
used to test the recent permissions fixes, and it ended up creating a
package with some files set to 600 and 700. This fix should prevent such
issues from happening, regardless of what permissions files happen to be
created with at build time.

Author: nickelization

priv/templates/deb/postinst

@@ -30,7 +30,9 @@ chmod 0755 /var/run/{{package_install_name}} /etc/{{package_install_name}}
 chmod 0644 /etc/{{package_install_name}}/*
 chmod -R +X /etc/{{package_install_name}}
 chmod 0755 /usr/lib/{{package_install_name}}/lib/env.sh
+chmod 0755 /usr/lib/{{package_install_name}}/lib/app_epath.sh
 chmod 0755 /usr/lib/{{package_install_name}}/erts-*/bin/nodetool
+chmod -R go+r /usr/lib/{{package_install_name}}/lib/
 
 case "$1" in
     configure)