nbd: new package nbd-server

Network block device server allows to export a block device from router
to remote host. This is particularly useful if no network filesystem
server is feasible or direct access to a block device is needed.

It's been tested for nearly a month on ar71xx (TL-WR842ND) and proved to
be very stable and efficient solution.
The package comes with init.d script and conf.d file allowing to
configure most nbd-server options using standard uci interface.

Signed-off-by: Marcin Jurkowski <marcin1j@gmail.com>
owfs: Add init scripts and config files

Owfs daemons lack control scripts. This patch adds init.d scripts for owfs,
owserver, owhttpd and owftpd packages.
Most daemon options (both common libow and program-specific parameters)
are reflected as uci config variables.

Signed-off-by: Marcin Jurkowski <marcin1j@gmail.com>
owfs: make libow features configurable

Owfs shared library is quite large (700+ kB) by embedded devices standards.
The code for many different bus master and slave devices is compiled
into single big .so library. Had it been designed as modular,
dynamic-loadable plugins, we could split them into separate packages,
allowing user to install only the plugins he needs.

It's however possible to enable or disable libow features at compile time.
Here are some examples how much space can be saved turning off support for
unneeded devices and features:
 - By disabling USB adapter support libusb and libusb-compat is no
   longer needed, saving ~70kB of space. Bus masters using usbserial.ko
   kernel driver don't need this.
 - By disabling debug messages it's possible to reduce shared library
   size by 130kB.

This patch adds a menu allowing user to select libow features he wants
built in:
 - Bus master support: USB adapters through libusb, i2c adapters, kernel w1
   adapters, HA7Net ethernet to 1-wire bridge
 - Slave device support: thermometers, ai8570 barometer
 - General features: zeroconf device announcement, cache, debug
   messages, owtraffic bus reports
Default config options preserve previous library configuration i.e.
everything is selected except for owtraffic (which was disabled) and
kernel w1 driver (whose netlink interface has been broken since 2011).

Signed-off-by: Marcin Jurkowski <marcin1j@gmail.com>
owfs: Bump version to 2.8p21

This patch bumps owfs version to 2.8p21.

It also includes a patch which fixes broken compilation when HA7Net
support is disabled.

Signed-off-by: Marcin Jurkowski <marcin1j@gmail.com>