Add support for uncommitted diseqc switch. - Take #2

Add support for uncommitted diseqc switch. - Take #2

This supports configurations that use uncommitted diseqc switch
in front of committed diseqc switch to allow 8/16 satellites...

Example of such cascade:

      19.2E  13E    16E  1W      5E 28.2E  23.5E 30W
          \   |      |   /        \   |      |   /
           \1  \2  3/  4/          \1  \2  3/  4/
         +--o---o--o---o--+      +--o---o--o---o--+ LNB (:dvb-satno n)
         | SPAUN SAR 411F |      | SPAUN SAR 411F |
         |    committed   |      |    committed   |
         +-----------o----+      +----o-----------+
                      \              /
                       \1          2/     sat:  switches:
         PORT        +--o----------o--+ 19.2E:  :dvb-uncommitted=1 :dvb-satno=1
(:dvb-uncommitted=n) | SPAUN SUR 211F |   13E:  :dvb-uncommitted=1 :dvb-satno=2
                     |  uncommitted   |   16E:  :dvb-uncommitted=1 :dvb-satno=3
                     +-------o--------+    1W:  :dvb-uncommitted=1 :dvb-satno=4
                             |             5E:  :dvb-uncommitted=2 :dvb-satno=1
                      +------o------+   28.2E:  :dvb-uncommitted=2 :dvb-satno=2
                      | skystar HD2 |   23.5E:  :dvb-uncommitted=2 :dvb-satno=3
                      +-------------+     30W:  :dvb-uncommitted=2 :dvb-satno=4

Reception of 16 satellites is possible using eg. SPAUN SUR 420F as uncommitted
diseqc switch instead of SPAUN SUR 211F, and 2 more SPAUN SAR 411F committed
diseqc switches.

Signed-off-by: Rémi Denis-Courmont <remi@remlab.net>