contributing: mention "rejected features" wiki page

Add support for WHR-HP-G300N

Add support for TP-Link TL-WA901ND v1

gluon-luci-private-wifi: typo seperaten

Using a loop makes the script a bit nicer, and it works around a git bug
corrupting patch dates when multiple patches are applied at once.

Add support for x86-xen_domu target

contrib/sigtest.sh - testing signature

Französische Übersetzung 

This also takes us past the OpenWrt 15.05 final release.

Build requires Python 2 and libssl-dev

docs: Suggest MTU 1280 to circumvent Kabel Deutschland problems

docs: Suggest peer limit 1 instead of 2

CONTRIBUTING.md: Typo "everybode"

Config for rootfs and grub is not needed anymore (https://dev.openwrt.org/ticket/18074)

Config file not needed anymore (set implicitly by gluon now)

Avoid empty vars

add: info for 802.11s interface (mac)

additional information for commit 2a93c580

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

Now that the status page api has been rewritten in C CPU load and memory
usage is much lower. Also, nodes with both ibss and 11s mesh and dual
band wifi may require up to 9 connections for a single client, thus the
previous limit of 12 seemed a little low.