patches: change default dhcp leasetime to 5 minutes

Related ticket: https://github.com/freifunk-berlin/firmware/issues/168
patches: fix ascii art in /etc/banner
[feeds] update packages_berlin

This should include fixes for:

* https://github.com/freifunk-berlin/firmware/issues/150
* https://github.com/freifunk-berlin/firmware/issues/163
Revert "patches: fix ascii art in /etc/banner"

This reverts commit 9c8394c6ace2c17c9e9f2b4df10ca423c029f6d0.

I added my changes to the wrong patch for whatever reason.
patches: fix ascii art in /etc/banner
Merge branch 'features/dhcp_lease_time'

This merge should set the dhcp lease time for new routers to 5 minutes.
Merge branch 'update/packages_berlin'

Collectd problem tested by Maria and me.
Leaflet lazy loading tested by Yves and me.
remove 4MB constraint from mikrotik profile
Merge branch 'mikrotik-profile'

Seems like most mikrotik devices have flash ics with a size greater than 4MB:

http://wiki.openwrt.org/toh/start#mikrotik

Fixes https://github.com/freifunk-berlin/firmware/issues/186.
[configs]: build ath{5,9,10}k wifi drivers as modules for x86 target

Most x86 boards support a wide range of wifi cards etc. because of the pci slots
they provide. The set of atheros drivers is quite common and was requests by
a user.
build and integrate freifunk-berlin-migration package into firmware
[feeds] update packages_berlin feed

Contains fixes a fix for htmode and a new migration package/script.
Merge branch 'features/x86_wifi_drivers'
Update OpenWRT to r43215

Patch '006-target-imagebuilder-remove-initramfs-dep.patch' is not needed
anymore because it is already included upstream.
Update OpenWrt revision to 43770.

Includes a fix for:

https://github.com/freifunk-berlin/firmware/issues/160