Backport of r48279

fix rescue mode on wdr4900

Backport of r48793

This option will make the generated commit IDs deterministic, greatly
reducing the number of repository objects created when calling `make
update` repeatedly.

brcm2708-gpu-fw: move pkg build dir to kernel build dir to fix rebuild bugs after cleaning the kernel tree

Backport of r48732

Mobile browsers will often show or hide the address bar while scrolling.
This causes resize events which would often reset the signal graphs.

Fixes #662

The bootloader of AirOS 5.6.x doesn't remove the flash protection for us,
so we have to do this ourselves.

This should fix problems with flashing from AirOS 5.6.x.

gluon-core: add preserve wifi channel feature

docs: fix typo in authorized keys config example

Ethernet links provide transitive connectivity in all but very unusual
setup, enable mesh_no_rebroadcast to reduce load for devices on links with
many nodes.

Fixes #652

This new feature introduces the new uci section 'gluon-core.wireless' with a preserve_channels option:
 * preserve_channels (boolean)

By setting this option to 1 (true) wifi channels will be preserved during upgrades.

Backport of r47591 and r48427

Should be redundant after 0bd0df6f

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

Change the limit to match our recommendation in the site-example.

We're too close to the release of Gluon 2016.1 to do a full update of our
OpenWrt tree, therefore just make a backport of this.

Fixes #558

Restrict to link-local addresses to prevent amplification attacks from
outside the mesh, or such attacks affecting the outside world.

Fixes #637

Fixes #574