overflow for 'DejaVu Sans'.

This renames the local_client zone to loc_client, as local_clint exceeds
the maximum zone length allowed for firewall3, which is 11 bytes.

This worked previously due to firewall3 using unsafe string operations.
Now creation of the chain fails (latest OpenWrt master).

This adds the wireless client count for 2.4GHz and 5 GHz radios to the
status page. Previously, only the total client count advertised by
the mesh protocol was visible.

This reverts commits
- caf2dd03.
- 07ebac6a
- 55eff45f

I accidentally pushed these commits as I had them lying around on a
dirty checkout I did testing on.

The original commit only applied its changes to the source file and did
not rebuild the minified file, therefore the change never went live.

Fixes: #659
Signed-off-by: Martin Weinelt <martin@darmstadt.freifunk.net>

Let gluon-respondd expose "MemAvailable" from /proc/meminfo to allow for
a more realistic memory-usage estimation.

Information on MemAvailable can be found here:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/
commit/?id=34e431b0ae398fc54ea69ff85ec700722c9da773

The field was accidentally removed during the status-page rewrite.

Fixes #1401

batman-adv-specific parts are moved to a new package
gluon-status-page-mesh-batman-adv.

gluon-status-page: reduce usage of absolute paths in cgi-bin scripts neighbours-nodeinfo and stations

The field is unused.

Some HTTP endpoints were writing annoying "broken pipe" messages to stderr.