MEDIUM: Paramatise functions over the check of a server

MEDIUM: Paramatise functions over the check of a server

Paramatise the following functions over the check of a server

* set_server_down
* set_server_up
* srv_getinter
* server_status_printf
* set_server_check_status
* set_server_disabled
* set_server_enabled

Generally the server parameter of these functions has been removed.
Where it is still needed it is obtained using check->server.

This is in preparation for associating a agent check
with a server which runs as well as the server's existing check.
By paramatising these functions they may act on each of the checks
without further significant modification.

Explanation of the SSP_O_HCHK portion of this change:

* Prior to this patch SSP_O_HCHK serves a single purpose which
  is to tell server_status_printf() weather it should print
  the details of the check of a server or not.

  With the paramatisation that this patch adds there are two cases.
  1) Printing the details of the check in which case a
     valid check parameter is needed.
  2) Not printing the details of the check in which case
     the contents check parameter are unused.

  In case 1) we could pass SSP_O_HCHK and a valid check and;
  In case 2) we could pass !SSP_O_HCHK and any value for check
  including NULL.

  If NULL is used for case 2) then SSP_O_HCHK becomes supurfulous
  and as NULL is used for case 2) SSP_O_HCHK has been removed.

Signed-off-by: Simon Horman <horms@verge.net.au>