docs: Improve documentation of fastd and autoupdater config in site.conf

Fixes #589

docs: releases/v2015.2: add ubiquiti airgateway

On the status page statistics section counters for transmitted and received traffic were mixed up. Transmitted traffic was shown as received while received traffic was shown as being transmitted.

Fixes #586

OpenSSL: Added source/old to PKG_SOURCE_URL

OpenSSL moves old versions of the library from http://www.openssl.org/source/
to http://www.openssl.org/source/old/1.0.2/ breaking the old links. That
behavior breaks the OpenWRT-build every time OpenSSL releases a new version.

This patch adds http://www.openssl.org/source/old/1.0.2/ to the PKG_SOURCE_URL
of OpenSSL to avoid breaking the build whenever OpenSSL releases a new
version.

Fixes #579

docs: add v2015.2 release notes

gluon-luci-private-wifi: fix typo in code file and regenerate translation files (correctly this time)

targets/ar71xx-generic: add WD MyNet N600/N750

docs: add link to tecff/site-ffa (Altdorf, Landshut & Umgebung)

Signed-off-by: Felix Kaechele <felix@kaechele.ca>

-spelling

Also
* create list of newly supported devices since v2015.1.2 in the v2015.2 release notes
* update information on docs/user/x86
* fix a comment in targets/ar71xx-generic/profiles.mk

gluon-mesh-batman-adv-core: keep disabled state even when the mesh interface section name is changed

Fix typo in LICENSE

This patch is already included in the current OpenWrt CC branch.
Cherry-pick for now as we're very close to the Gluon 2015.2 release.

In line 2: indiviual -> individual