Fixes #550

Fixes #540

Update kernel to 3.18.23

ath9k expects to get revision id 2 for the QCA9531 ver. 2 rev. 0. This
fixes the very low TX power on some devices like the TP-LINK
TL-WR841ND v10.

As ath79_soc_rev is only used to get the revision number to ath9k on the
QCA9533, just set it to the expected value on the ver. 2.

Some more cleanup.

This patch adds the kernel modules to for the very common Realtek RTL8150 and Realtek 8152 based USB-to-Ethernet converters.
After this patch the following packages can be added to targets (or site.mk):
kmod-usb-net-rtl8150
kmod-usb-net-rtl8152

The modules are already available in openwrt trunk, but not in Chaos Calmer. This patch is just a temporary backport.
The modules are needed for Futros with additional USB-Ethernet-Interface and VMs with dedicated USB-NIC

This reverts commit 8ad3c881.

We can't use the same image for these two devices, so as a workaround,
remove ZR-600DHP from the name for now, so the autoupdater can work and
users aren't confused.

This also takes us past the OpenWrt 15.05 final release.

LuCI's authentication won't work without rpcd, but we aren't using the
authentication anyways. Users who need it can just install rpcd explicitly.

Fixes #452

This reverts commit 91b3c1d3.

This reverts commit 6da1677d.

Apart from replacing a patch for the former by two patches for latter,
this involved minimal adaptations of the lua scripts in the following
packages:

* gluon-announce
* gluon-announced
* gluon-mesh-batman-adv-core
* gluon-status-page

Fixes site.conf checks.

This also updates batman-adv & alfred to 2015.1

This should workaround batman-adv's inability to deal with different MTUs
which need fragmentation.

Fixes #435

This might improve stability on the TL-WR841 v9.