basic user-space for pinned-spans

handle_device is the basic script intended to be called from udev.

It will call span_types on the span to apply optional
/etc/dahdi/spantype.conf onfiguration settings that need to be applied
before assignment (currently "pri" port types: E1/T1/J1).

Next it assigns span numbers to spans: if configured in
/etc/dahdi/pinned-spans.conf - use those settings. If not: by the order
of loading.

span_types and span_assignments can also be used to report the settings
they are used to configure.

Signed-off-by: Oron Peled <oron.peled@xorcom.com>
Signed-off-by: Tzafrir Cohen <tzafrir.cohen@xorcom.com>
Signed-off-by: Russ Meyerriecks <rmeyerriecks@digium.com>
Make udev run dahdi_cfg on each device:

 * New script: dahdi_cfg_device_args:
   - Just like span_assignments, span_types: may be given
     one or more sysfs devpath's
   - Output the required options for dahdi_cfg. E.g:
       "-S 8 -C 15-28"
   - This may be passed (with any other wanted options)
     to the new dahdi_cfg (which supports '-S' and '-C')

 * Use dahdi_cfg_device_args in handle_device so we configure
   each span from udev.

Signed-off-by: Oron Peled <oron.peled@xorcom.com>
Signed-off-by: Russ Meyerriecks <rmeyerriecks@digium.com>
optionally install pinned files: --enable-pinned

Add installation of the pinned-spans support to the Makefile. For the
moment, however, they are not installed unless you use ./configure
--enable-pinned or build with 'make DAHDI_PINNED=yes'

Signed-off-by: Tzafrir Cohen <tzafrir.cohen@xorcom.com>
Signed-off-by: Russ Meyerriecks <rmeyerriecks@digium.com>
Update the configure script as well.

Signed-off-by: Tzafrir Cohen <tzafrir.cohen@xorcom.com>
Signed-off-by: Russ Meyerriecks <rmeyerriecks@digium.com>