Revert "removed swap prio from fstab.semc | will be set by init.d script on boot"

This reverts commit b3e218c7138a66ce31762beb250e080fc632779d.
Revert "(re-)added swap prio"

This reverts commit d1414e90159e095e34eb1e0ffc6093cd894b4d1a.
Revert "fixed mount options of zram devices"

This reverts commit 5f200ba44aba2edd7fda58059677fe7042b7889c.
Revert "default zRam devices to 4 instead of 1"

This reverts commit 6df91b82215fec3c385864606a098a73b3f57376.