span_types/assignments: no * in device list

If there are no dahdi devices, $devbase/* expans to have a literal '*',
which leads to warnings such as:
/usr/sbin/dahdi_span_types: 1: cd: can't cd to /sys/bus/dahdi_devices/devices/*

Let's just avoid those.

Signed-off-by: Tzafrir Cohen <tzafrir.cohen@xorcom.com>
dahdi_genconf: don't generate spantypes by default

A sane value for span-types.conf is either "all E1" or "all T1". Either
way it is not hardware-dependent, and hence no point in regenerating on
when the hardware changes.

Signed-off-by: Tzafrir Cohen <tzafrir.cohen@xorcom.com>
dahdi_genconf: Add 'modules', 'spantypes', and 'assignedspans' to list of available generators.

This is a documentation change, that hopefully will help until I can remember
the names of the new generators.

Signed-off-by: Shaun Ruffell <sruffell@digium.com>
Acked-by: Tzafrir Cohen <tzafrir.cohen@xorcom.com>
dahdi_span_types: Show location of configuration file in help message.

Makes similar in for the dahdi_span_assignments in that the location of the
default configuration file is shown in the help screen.

Signed-off-by: Shaun Ruffell <sruffell@digium.com>
Acked-by: Tzafrir Cohen <tzafrir.cohen@xorcom.com>
dahdi_handle_device: Auto assign only the device being added.

Eliminates trying to add spans multiple times as seen below:

    'dahdi_handle_device'[21993]: add: /devices/dynamic:loc:1
    'dahdi_handle_device'[21991]: add: /devices/dynamic:loc:0
    'dahdi_handle_device'[22001]: auto-assign /sys/bus/dahdi_devices/devices/dynamic:loc:0
    'dahdi_handle_device'[22001]: auto-assign /sys/bus/dahdi_devices/devices/dynamic:loc:1
    'dahdi_handle_device'[21999]: auto-assign /sys/bus/dahdi_devices/devices/dynamic:loc:0
    'dahdi_handle_device'[21999]: auto-assign /sys/bus/dahdi_devices/devices/dynamic:loc:1
    kernel: [ 3348.312534] dahdi_devices dynamic:loc:0: local span 1 is already assigned span 1
    kernel: [ 3348.312552] dahdi_devices dynamic:loc:1: local span 1 is already assigned span 2

Signed-off-by: Shaun Ruffell <sruffell@digium.com>
Acked-by: Tzafrir Cohen <tzafrir.cohen@xorcom.com>